KR20060011338A - Photoreceiver with Single Photodiode - Google Patents

Abstract

The optical receiver having a single photodiode of the present invention is intended to provide a low-cost optical receiver to consumers by reducing the number of parts attached to the optical receiver and simplifying the circuit, and more specifically, broadcasting and communication. When a plurality of broadcast signals generated at a transmitting side providing a service are converted into optical signals and transmitted to a receiving side through an optical fiber, a single photodiode 10 of the receiver receives the optical signals and corresponds to a plurality of broadcast signals. Optical signal having a single photodiode that converts the signals and transmits the electrical signal to each signal processing module (100, 200) connected to both ends of the photodiode (10) on a closed circuit to output a broadcast signal suitable for the terminal. To a receiver.

Optical Communication, Optical Transceiver Module, Photo Diode, Optical Receiver

Description

Optical Receiver Having A Single Photodiode             

1 is a view schematically showing a transmission system of a general optical communication;

2 is a circuit block diagram of a conventional optical receiver;

3 is a circuit block diagram of an optical receiver having a single photodiode according to an embodiment of the present invention;

4 is an overall circuit diagram showing an application of an optical receiver with a single photodiode based on an embodiment of the present invention.

* Description of the main parts of the drawings *

10: photodiode 20: first matching circuit

21: second matching circuit 30: first filter

31: second filter 32: third filter

33: fourth filter 40: first amplifier

41: second amplifier 42: third amplifier

43: fourth amplifier 50: the first output unit

51: second output unit 52: third output unit

53: fourth output unit 60: equalizer

61: first gain controller 62: first signal attenuator

63 second gain controller 64 second signal attenuator

100: first signal processing module 200: second signal processing module

The present invention relates to an optical receiver built in an optical transceiver module installed in a home of each home, and loads a plurality of broadcast signals and receives an optical signal transmitted through an optical cable from a photodiode of an optical receiver without using an optical coupler. The present invention relates to an optical receiver having a single photodiode for converting a signal, separating a plurality of broadcast signals, and then converting the broadcast signal to a suitable output signal.

FTTH (FIBER TO THE HOME) enables all services including broadcasting and communication by connecting one optical cable to the subscriber's premises and is the most ideal optical subscriber network in terms of bandwidth.

However, in the FTTH network, the optical cable must be connected to the home, and the optical transmission / reception module for converting the optical signal and the electrical signal must be installed in each house separately. Is being used.

Therefore, the WDM (Wavelength Division Multiplexing) transmission method and PON (Passive Optical Network), which allow simultaneous transmission and reception of heterogeneous signals and bidirectional transmission of heterogeneous signals to one optical cable, that is, simultaneous transmission and reception of digital data signals and broadcast signals through optical signals having different wavelengths. As the system is applied to optical communication, the frequency band is widened and the synchronization procedure is not necessary, so the optical transmission / reception module equipment is also simplified, thereby speeding up the implementation of the FTTH network, which is the ultimate goal of the optical subscriber access technology.

As the optical transmission module market is activated, development of optical transmission modules such as optical modules, small and medium modules incorporating optical transmission modules, and Ethernet and asynchronous transmission methods (ATM), which correspond to 10Gbps high-speed information and communication networks ought.

In general, the optical transmission module is used for digital data communication such as Internet data or VoIP. Recently, however, interest in communication and broadcasting convergence services that can transmit and receive video and broadcast signals together, such as VOD (Video On Demand), CATV, and satellite broadcasting, is increasing and demand is expected to increase.

In the conventional optical receiver, in order to receive a plurality of analog broadcast signals transmitted from a transmitter such as CATV and satellite broadcast simultaneously, a plurality of photo diodes of a receiver corresponding to the optical signals converted and transmitted from the transmitter are respectively provided. After receiving the light, converting it into an electric signal and outputting it through a signal processing module is not only complicated the circuit of the receiver but also requires the use of a plurality of photodiodes with the highest weight in terms of the price of the receiver. In addition, since an optical device called an optical coupler must be separately mounted at the end of the optical connector, system construction for optical communication becomes complicated and causes high cost.

1 is a schematic diagram of a transmission system of optical communication, and optical communication is mainly composed of three parts: an optical transmitter, an optical fiber, and an optical receiver.

When the transmitting end generating the analog broadcasting signal or data communication signal such as CATV or satellite broadcasting transmits the signals to the optical transmitter, the optical transmitter converts the electrical signals into optical signals and moves them to the optical receiver on the receiving side through the optical fiber.

The photodiode of the optical receiver irradiated with the optical signal including a plurality of broadcast signals converts the optical signal into an electrical signal and converts the electrical signal through a signal processing module having an amplifier and a filter. It is output through the output terminal.

2 shows a circuit block diagram used in a typical receiver.

The receiver of the example of FIG. 2 is characterized by using a plurality of photodiodes and is the easiest and most common method for receiving and restoring broadcast signals transmitted simultaneously.

Signals from CATV and satellite broadcasting are mixed and converted into optical signals and transmitted to the receiver. The signals of one channel are divided into two by an optical coupler and irradiated to each photodiode.

The electric signal irradiated to PD1 passes through the matching circuit, and only the CATV signal is passed by the LPF (Low Pass Filter) to be output to the CATV output unit.

In addition, the electric signal irradiated to the PD2 passes through a matching circuit, and only satellite broadcast signals such as SKY LIFE pass through the HPF (High Pass Filter) to be output to the satellite broadcast output unit.

This configuration can be easily implemented as a product without any technical problems because there is no electrical interference between the two signals (CATV, satellite broadcasting), but the cost is increased by using two or more relatively expensive photodiodes.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, and a single photodiode receives a light signal containing a plurality of broadcast signals and converts the light signal into an electric signal, thereby simplifying the circuit of the optical receiver. In addition, since it uses only one photodiode and does not need a separate optical coupler, it can be easily installed in a consumer's house at a low price. Its purpose is to provide a high-performance and high-efficiency optical receiver that can accelerate the implementation of converged broadcasting services.

An object as described above is a photo diode and a photo diode coupled to receive an operating power (Vcc) from a power supply unit to receive an optical signal including a plurality of broadcast signals and to convert and output corresponding electrical signals. The first signal processing module connected to the photodiode and the electrical signal converted in the photodiode are processed into a high frequency band output signal to process the electrical signal converted from the diode into a low frequency band output signal and output it to a terminal. And a second signal processing module connected to the photodiode to output to the terminal, wherein the optical signal irradiated to the photodiode on the closed circuit to which power is applied is converted into an electrical signal and connected to both ends of the photodiode. It is characterized in that the impingement respectively to the signal processing module and the second signal processing module. Is achieved by a photoreceiver with a single photodiode.

In addition, according to the present invention, the first signal processing module is provided at the output terminal of the first matching circuit and the first matching circuit having an input terminal connected to give a constant resistance value to the electrical signal at one side of the photodiode to match the impedance. A first filter having an input connected to pass only a corresponding frequency band among impedance-matched electric signals, and a first having an input connected to amplify the signal magnitude of the electric signal passing through the first filter at an output of the first filter It is preferable to include a first output unit having an input terminal connected to output an amplifier and an electrical signal amplified at the output terminal of the first amplifier to the terminal and an output port of the corresponding communication standard.

In addition, according to the present invention, the second signal processing module is provided at the output terminal of the second matching circuit and the second matching circuit having an input terminal connected to give a constant resistance value to the electrical signal on the other side of the photodiode to match impedance. A second filter having a second amplifier having an input coupled to amplify the magnitude of the electrical signal passing through the second matching circuit and an input stage coupled to pass only a corresponding frequency band of the electrical signal amplified at the output of the second amplifier; And a second output unit having an input terminal connected to output an electrical signal passing through the second filter through the terminal at an output terminal of the second filter and an output port of a corresponding communication standard.

In addition, according to the present invention, the first filter is preferably configured to be circuitry so as to pass only signals in the frequency band of 50MHz to 870MHz.

In addition, according to the present invention, the second filter is preferably configured to be circuitry so as to pass only signals in the 950MHz to 2.1GHz frequency band.

In addition, according to the present invention, a second input circuit having an input terminal connected to receive an electrical signal in parallel from the output terminal of the second matching circuit and amplify the signal magnitude of the electrical signal passing through the second matching circuit at the output terminal of the second matching circuit. A third filter having an input terminal connected to pass only a corresponding frequency band among the electrical signals amplified at the output terminal of the third amplifier and the third amplifier and an electrical signal passing through the third filter at the output terminal of the third filter; It is preferable to further include a third output unit having an input connected to the output via the output code of the communication standard.

In addition, according to the present invention, a second input circuit having an input terminal connected to receive an electrical signal in parallel from the output terminal of the second matching circuit and amplify the signal magnitude of the electrical signal passing through the second matching circuit at the output terminal of the second matching circuit. A fourth filter having an input terminal connected to pass only a corresponding frequency band among the electrical signals amplified at the output terminal of the fourth amplifier and the fourth amplifier and an electrical signal passing through the fourth filter at the output terminal of the fourth filter; It is preferable to further include a fourth output unit having an input connected to the output through the output code of the corresponding communication standard.

In addition, according to the present invention, the third filter is preferably configured to be circuitry so as to pass only signals in the 2.3 GHz frequency band.

In addition, according to the present invention, the fourth filter is preferably configured to be circuitry so as to pass only signals in the 2.6 GHz frequency band.

Hereinafter, preferred embodiments of the present invention will be described through the accompanying drawings.

3 is a circuit block diagram of an optical receiver having a single photodiode according to an embodiment of the present invention.

A PIN photodiode was used as a light receiving element of the optical receiver. The PIN photodiode is a PIN photodiode formed by bonding semiconductors doped with P-type and N-type to both surfaces of a semiconductor to which no impurities are added. When light enters the semiconductor region that is not added, it is absorbed to form an electron-hole pair and split by the electric field. Thus, it is a diode that is used to generate laser current, demodulate mixed modulated light, or perform high speed optical detection or various optical data processing. .

The photodiode 10 is on a closed circuit to which power is supplied, and the first signal processing module 100 and the second signal processing module 200 are connected to both ends of the photodiode 10.

The signal processing module 100 is a circuit stage in which the matching circuit 20, the filter 30, the amplifier 40, and the output unit 50 are connected in series, and the electrical signal converted by the photodiode 10 is converted. Performs signal processing to output to the terminal.

The signal processing module 200 is a circuit stage in which the matching circuit 21, the amplifier 41, the filter 31, and the output unit 51 are connected in series, and performs the same signal processing as the signal processing module 100. To perform.

The first matching circuit 20 is a circuit inserted to transmit the least power loss by equalizing the conjugate value of the impedance of the output terminal of the photodiode and the output terminal impedance of the photodiode when the two circuits are electrically coupled. In this way, the photodiode 10 and the first filter 30 are connected in a circuit.

The second matching circuit 21 has a circuit configuration identical to or similar to that of the first matching circuit, and is electrically connected between the photodiode 10 and the second amplifier 41 and has an impedance value of 75Ω. .

The first filter 30 is an electronic circuit that passes only a signal waveform of a desired shape and filters out unwanted waveforms. The first filter 30 generally includes a combination of an inductance L and a capacitance C. The first filter 30 includes a first matching circuit. A connection between the 20 and the first amplifier 40.

LPF (Low Pass Filter) for passing signals below a certain frequency when the filters are classified functionally, HPF (High Pass Filter) for passing only signals above a certain frequency, and BPF (Band Pass Filter) for passing signals in any frequency band The first filter 30 corresponds to a low pass filter (LPF) that passes only the 50 MHz to 870 MHz band, which is a CATV frequency band.

The second filter 31 has the same or similar circuit configuration as that of the first filter 30 and is connected between the second amplifier 41 and the second output unit 51 and is a frequency band of SKY LIFE, satellite broadcasting, 950 MHz. Corresponds to BPF (Band Pass Filter) which passes only the ~ 2.1GHz band.

The third filter 32 has the same or similar circuit configuration as that of the first filter 30 and is connected between the third amplifier 42 and the third output unit 52, which is a frequency band of the portable Internet service 2.3. Corresponds to BPF (Band Pass Filter) which passes only GHz band.

The portable Internet service refers to a service that uses a variety of information and content by accessing the Internet at a high transmission speed in a stationary or walking state using a portable wireless terminal.

The fourth filter 33 has the same or similar circuit configuration as that of the first filter 30 and is connected between the fourth amplifier 43 and the fourth output unit 53, and the satellite digital multimedia broadcasting (DMB) service is provided. Corresponds to the BPF (Band Pass Filter) that passes only the 2.6 GHz band.

Satellite DMB service launches satellites outside the atmosphere, spreading broadcast signals in a frequency band (2.6 GHz) much higher than terrestrial DMB, and terrestrial repeaters relay this signal. It is a personal multimedia satellite broadcast spread to the public.

The first amplifier 40 is circuit-connected between the first filter 30 and the first output unit 50.

The amplifier is a device that increases the energy of the input signal and outputs it as an output signal. The first amplifier uses a low noise amplifier to amplify only a necessary signal with little noise amplification.

The second amplifier is circuit-connected between the second matching circuit and the second filter and has the same or similar circuit configuration as the first amplifier.

The third amplifier is circuit-connected between the second matching circuit and the third filter and has the same or similar circuit configuration as the first amplifier.

The fourth amplifier is circuit-connected between the second matching circuit and the fourth filter and has the same or similar circuit configuration as the first amplifier.

The first output unit is connected to the first amplifier and outputs the CATV signal to the terminal for reproduction.

The second output unit is connected to the second filter and outputs a satellite broadcast signal such as SKY LIFE to the terminal for reproduction.

The third output unit is connected to the third filter and outputs the wireless portable Internet service signal to the terminal for playback.

The fourth output unit is connected to the fourth filter and outputs the satellite DMB service signal to the terminal for reproduction.

As shown in FIG. 3, when an optical signal of CATV and satellite broadcasting is irradiated to a photodiode 10 on a closed circuit to which power is applied, the photodiode 10 converts the received optical signal into an electrical signal and the electrical signal. Flows to the signal processing modules 100 and 200 connected to both ends of the photodiode 10.

Of the electrical signals entering the first signal processing module 100 on one side, only the CATV signal, which is a low frequency band, passes through the first filter 30 and is amplified by an amplifier, and then is transmitted to the CATV terminal by the first output unit 50. Is the output.

Of the electrical signals entered into the second signal processing module 200 on the other side is amplified by the second amplifier 41 and then only the signal of the satellite broadcasting frequency band passes through the second filter 31 and the second output unit 51 ) Is output to the satellite broadcasting terminal.

The electrical signal entering the second signal processing module 200 is amplified by the third amplifier 42 connected in series to the second matching circuit 21 and then passes only the portable Internet service signal through the third filter 32. The third output unit 52 outputs the output to the portable Internet service terminal.

The electrical signal entering the second signal processing module 200 is amplified by the fourth amplifier 43 connected in series to the second matching circuit 21 and then only the satellite DMB signal is passed through the fourth filter 33. The fourth output unit 53 outputs the satellite DMB terminal.

In addition, another circuit stage in which an amplifier, a filter, and an output unit are sequentially combined may be connected in series with the second matching circuit 21, and may receive another wideband signal and output it to a corresponding terminal.

4 shows an overall circuit diagram of an optical receiver having a single photodiode according to a preferred embodiment of the present invention.

The photodiode 10 receives the optical signals from the connector of the optical cable and converts the optical signals into electrical signals. The electrical signals converted from the photodiode 10 on the closed circuit are connected in parallel across the circuit and matched circuits, filters, and equalizers. The same flows into the signal processing module, which consists of a low noise signal amplifier, a gain controller, a signal attenuator and an output.

The electrical signal converted by the photodiode 10 is transmitted to the first matching circuit 20 on one side connected in parallel with the circuit, and the impedance of the electrical signal is matched by a constant resistance value.

 In the first matching circuit 20, the impedance matched electrical signal is transmitted to the input terminal of the first filter 30 connected to the output terminal of the first matching circuit 20, at which time only the signal of the CATV frequency band passes. .

The electrical signal passing through the first filter 30 is transmitted to the input terminal of the equalizer 60 connected to the output terminal of the first filter 30, where the frequency characteristics of the various channels of the CATV band are uniformly adjusted.

The electrical signal passing through the equalizer 60 is transmitted to the input terminal of the first amplifier 40 connected to the output terminal of the equalizer 60, and the first amplifier 40 lowers the noise figure of the entire receiver.

The electrical signal passing through the first amplifier 40 is transmitted to the input terminal of the first gain controller 61 connected to the output terminal of the first amplifier 40 to adjust the amplification and attenuation change of the first amplifier 40. do.

The electrical signal passing through the first gain controller 61 is transmitted to an input terminal of the first amplifier 40 connected to the output terminal of the first gain controller 61, and the first amplifier 40 measures the noise figure of the entire receiver. Will be lowered.

The electrical signal passing through the first amplifier 40 is transmitted to the input terminal of the first signal attenuator 62 connected to the output terminal of the first amplifier 40 and the first signal attenuator 62 causes the input signal power to be attenuated. do.

The electrical signal passing through the first signal attenuator 62 is transmitted to the first output unit 50 connected to the output terminal of the first signal attenuator 62. The transmitted electrical signal is wirelessly transmitted to the corresponding terminal for reproduction. do.

The electrical signal converted by the PIN photodiode 10 is transmitted to the second matching circuit 21 on the other side connected in parallel with the circuit, and the impedance of the electrical signal is matched by a constant resistance value.

 In the second matching circuit 21, the impedance-matched electrical signal is transmitted to the input terminal of the second amplifier 41 connected to the output terminal of the second matching circuit 21, and the second amplifier 41 is connected to the entire receiver. This lowers the noise figure.

The electrical signal passing through the second amplifier 41 is transmitted to the input terminal of the second filter 31 connected to the output terminal of the second amplifier 41, and the second filter 31 passes only the frequency of the satellite broadcasting band. Do it.

The electrical signal passing through the second filter 31 is transmitted to the input terminal of the second gain controller 63 connected to the output terminal of the second filter 31, and the second gain controller 61 amplifies the second amplifier. And attenuation change.

The electrical signal passing through the second gain controller 63 is transmitted to the input terminal of the second amplifier 41 connected to the output terminal of the second gain controller 63, and the second amplifier 41 is the noise figure of the entire receiver. To lower it.

The electrical signal passing through the second amplifier 41 is transmitted to the input terminal of the second signal attenuator 64 connected to the output terminal of the second amplifier 41, and the second signal attenuator 64 receives the input signal power. Will be attenuated.

The electrical signal passing through the second signal attenuator is transmitted to the second output unit 51 connected to the output terminal of the second signal attenuator. The transmitted electrical signal is wirelessly transmitted to the corresponding terminal for reproduction.

As described in detail above, the optical receiver equipped with the single photodiode of the present invention simplifies the circuit and produces the product since the single photodiode receives the optical signal including the plurality of broadcast signals and converts the signal into an electrical signal. It can increase.

 In addition, since the optical receiver equipped with a single photodiode of the present invention can reduce the number of photodiodes, which are the most expensive in the optical receiver, to one, the consumer can purchase the optical receiver at a low price.

In addition, the optical receiver equipped with a single photodiode of the present invention has the effect of spreading the distribution of optical transmitting and receiving modules in each household, thereby further facilitating the implementation of the FTTH network in which communication and broadcasting are converged.

Claims (9)

When a plurality of electrical signals generated by a transmitter providing an analog broadcast and communication service are converted into optical signals and transmitted to a receiver through an optical fiber, the optical signals are received and restored to an electrical signal, and the mixed electrical signals are mixed. In the optical receiver having a power supply unit to divide the frequency band and output to the terminal, A photo diode (10) coupled to receive the operating power (Vcc) from the power supply unit to receive an optical signal including a plurality of broadcast signals and to convert and output an electrical signal corresponding thereto; A first signal processing module (100) connected to the photodiode (10) for processing the electrical signal converted by the photodiode (10) as a low frequency output signal and outputting it to a terminal; A second signal processing module 200 connected to the photodiode 10 to process the electrical signal converted by the photodiode 10 into a high frequency band output signal and output the same to a terminal;  An optical signal irradiated to the photodiode 10 on a closed circuit to which power is applied is converted into an electrical signal and respectively provided to the first signal processing module 100 and the second signal processing module 200 connected to both ends of the photodiode. An optical receiver having a single photodiode, characterized in that being transferred. The method of claim 1, The first signal processing module (100) includes a first matching circuit (20) having an input terminal connected at one side of the photodiode (10) to give a predetermined resistance value to the electrical signal to match an impedance;  A first filter (30) having an input terminal connected to pass only a corresponding frequency band among electrical signals having an impedance match at the output terminal of the first matching circuit (20);  A first amplifier (40) having an input connected at the output of the first filter (30) to amplify the signal magnitude of the electrical signal passing through the first filter (30); A first output unit 50 having an input terminal connected to output the amplified electric signal at the output terminal of the first amplifier 40 to the terminal and an output port of a corresponding communication standard; Optical receiver having a single photodiode comprising a. The method of claim 1, A second matching circuit (21) having an input terminal connected at the other side of the second signal processing module (200) to give a predetermined resistance value to match the impedance; A second amplifier (41) having an input connected at the output of the second matching circuit (21) to amplify the signal magnitude of the electrical signal passing through the second matching circuit (21);  A second filter (31) having an input connected to pass only a corresponding frequency band among the electrical signals amplified at the output of the second amplifier (41); A second output unit 51 having an input terminal connected to output an electrical signal passing through the second filter 31 through the terminal at an output terminal of the second filter 31 and an output port of a corresponding communication standard; Optical receiver having a single photodiode comprising a. The method of claim 2, The first filter (30) is an optical receiver having a single photodiode, characterized in that the circuit is configured to pass only signals in the frequency band 50MHz ~ 870MHz. The method of claim 3, wherein The second filter (31) is an optical receiver having a single photodiode, characterized in that the circuitry is configured to pass only signals in the 950MHz to 2.1GHz frequency band. The method of claim 3, wherein An input terminal connected to receive an electrical signal in parallel from an output terminal of the second matching circuit 21 and to amplify a signal magnitude of the electrical signal passing through the second matching circuit 21 at an output terminal of the second matching circuit 21. A third amplifier 42 having; A third filter (32) having an input connected to pass only a corresponding frequency band among the electrical signals amplified at the output of the third amplifier (42); A third output unit 52 having an input terminal connected to output an electrical signal passing through the third filter 32 through the terminal at the output terminal of the third filter 32 and an output code of a corresponding communication standard; Optical receiver having a single photodiode, characterized in that it further comprises. The method of claim 3, wherein An input terminal connected to receive an electrical signal in parallel from an output terminal of the second matching circuit 21 and to amplify a signal magnitude of the electrical signal passing through the second matching circuit 21 at an output terminal of the second matching circuit 21. A fourth amplifier 43 having a; A fourth filter (33) having an input connected to pass only a corresponding frequency band among the electrical signals amplified at the output of the fourth amplifier (43); A fourth output unit 53 having an input terminal connected to output an electrical signal passing through the fourth filter 33 through the terminal at the output terminal of the fourth filter 33 and an output code of a corresponding communication standard; Optical receiver having a single photodiode, characterized in that it further comprises. The method of claim 6, The third filter (32) is an optical receiver having a single photodiode, characterized in that the circuitry is configured to pass only signals in the 2.3GHz frequency band. The method of claim 7, wherein The fourth filter (33) is an optical receiver having a single photodiode, characterized in that the circuitry is configured to pass only signals in the 2.6 GHz frequency band.

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