JPH08237160A - Reception power control method and reception power controller - Google Patents

Abstract

PURPOSE: To make the controller small in size and to simplify the controller by throwing a high frequency switch to the position of transmission side in the case of reception upon the receipt of an attenuator control signal from the reception power controller so as to attenuate reception power depending on the isolation characteristic of the high frequency switch. CONSTITUTION: Upon the receipt of a reception attenuator control signal, a high frequency switch control circuit 19 connects terminals A, B of a high frequency switch 12 in the reception state to control the switch 12 so that reception is conducted by connecting a power amplifier 16 and a BPF 11. In the case of attenuator control, an input from an antenna 10 is given to a low noise amplifier 13 via the BPF 11 through the isolation effect between the terminals of the switch 12. Since the high frequency switch 12 has isolation of 20-30dB, the reception power received by the switch 12 is attenuated by the isolation of the switch 12 and then given to the low noise amplifier 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a received power control device for attenuating received power in a wireless device.

[0002]

2. Description of the Related Art Conventionally, a reception power control device of a radio device having a function of attenuating reception power monitors reception power,
When the received power exceeds a preset power, the received power is attenuated by controlling the attenuator circuit.

[0003]

The conventional received power control apparatus as described above uses an attenuator circuit for its attenuator control, so that the number of parts is increased and the parts cost is reduced. The increase in the number of components and the increase in the number of components hinder the miniaturization of wireless devices, making it extremely unsuitable for wireless devices that are particularly required to be lightweight and compact, such as mobile phones, and to operate the attenuator circuit. Since a power source is required for this and the current consumption increases, there is a problem in that the talk time is affected in a wireless device that operates on a rechargeable battery such as a mobile phone.

[0004]

A received power control apparatus according to the present invention is connected to an antenna and detects a received power at the time of receiving and a high frequency switch for switching connection of the antenna at the time of receiving and transmitting. When the power is equal to or higher than the preset power, the reception power control means that outputs the attenuator control signal, and the high frequency switch at the time of reception and transmission are respectively switched to the reception side and the transmission side, and the attenuator control signal from the reception power control means Is entered,
And a high frequency switch control circuit for switching the high frequency switch to the transmitting side at the time of reception.

[0005]

In the present invention, the high frequency switch connected to the antenna switches the connection of the antenna at the time of reception and at the time of transmission, and the reception power control means detects the reception power at the time of reception, and the reception power is preliminarily determined. When the power is above the set level, the attenuator control signal is output,
The high-frequency switch control circuit switches the high-frequency switch to the reception side and the transmission side at the time of reception and transmission, respectively, and when the attenuator control signal from the reception power control means is input, the high-frequency switch is switched to the transmission side at the time of reception. The received power is attenuated due to the isolation characteristics of the high frequency switch.

[0006]

1 is a block diagram showing the configuration of a radio apparatus having a received power control apparatus according to an embodiment of the present invention.
In the figure, 10 is an antenna, 11 is a bandpass filter, and 12 is a high-frequency switch. This high-frequency switch 12 is connected to the bandpass filter 11, and by switching the switch, reception and transmission are switched. ing.

Reference numeral 13 is a low noise amplifier for amplifying a reception signal input through the high frequency switch 12, and 14 is a mixture of an output signal of the low noise amplifier 13 and a reception local oscillation signal (hereinafter, referred to as reception local signal), A reception mixer that outputs a reception intermediate frequency signal (hereinafter referred to as a reception IF signal). The reception IF signal output from the reception mixer 14 is detected and amplified, and is output from a speaker (not shown) or the like. .

Reference numeral 16 denotes a transmission intermediate frequency signal (hereinafter referred to as a transmission IF signal) obtained by modulating / amplifying a signal input from a microphone (not shown) or the like and a transmission local oscillation signal (hereinafter referred to as a transmission local signal). Is a transmission mixer that mixes and outputs a transmission signal, and 16 is a power amplifier that amplifies the output signal of the transmission mixer 15 and outputs it to the bandpass filter 11 via the high-frequency switch 12.

A transmission / reception control circuit 17 outputs a transmission / reception switching control signal for controlling switching between transmission and reception.
8 is a reception power control circuit that receives a reception IF signal from the reception mixer 14 and outputs a reception attenuator control signal that controls reception power based on the reception IF signal. 19 is a transmission / reception switching control signal from the transmission / reception control circuit 17. And a reception attenuator control signal from the reception power control circuit 18, and is a high frequency switch control circuit for controlling switching of the high frequency switch based on the input transmission / reception switching control signal and the input reception attenuator control signal.

In this embodiment, a digital radio device for transmitting and receiving by a digital signal is used as the radio device, and the high frequency switch 12 can be switched between transmission and reception by the transmission / reception control circuit 17 every 5 mS, for example. The digital signals of the reception IF signal and the transmission IF signal are compressed / multiplexed so as to interlock with the switching, and communication is performed by a simultaneous call for simultaneous reception and transmission. Further, as the wireless device, a wireless device that switches between transmission and reception and performs separate reception and transmission may be used.

Next, the operation of the attenuator control of this embodiment will be described. FIG. 2 is an explanatory diagram for explaining the high frequency switch. First, the high frequency switch 12 is configured as shown in FIG. 2, the A terminal of the high frequency switch 12 is connected to the bandpass filter 11 as a common port, and the B terminal of the high frequency switch 12 is connected to the transmission side as a power amplifier. High frequency switch 1 connected to 16
The C terminal of 2 is a low noise amplifier 1 as a connection port on the receiving side.
It is connected with 3.

The high frequency switch 12 has a D terminal and an E terminal.
The terminal is connected to the high frequency switch control circuit 19 as a control terminal for switch control, and when a “H” level signal is input to the D terminal of the high frequency switch 12, the A terminal and the B terminal of the high frequency switch 12 are connected. Power amplifier 1
When the signal amplified in 6 is output to the bandpass filter 11 and the “H” level signal is input to the E terminal of the high frequency switch 12, the A terminal and the C terminal of the high frequency switch 12 are connected to each other, and the bandpass filter is connected. The signal from 11 is output to the low noise amplifier 13.

In normal communication, transmission / reception control is performed by the control of the transmission / reception control circuit 17. However, when the received power exceeds a preset power level, the received power control circuit 18 controls the power level. A reception attenuator control signal for detecting and performing attenuator control is output to the high frequency switch control circuit 19.

When the reception attenuator control signal is input, the high frequency switch control circuit 19 inputs a signal of "H" level to the D terminal of the high frequency switch 12 at the time of reception, and inputs it to the A terminal of the high frequency switch 12. The high frequency switch 12 is controlled so that reception is performed with the B terminal connected and the power amplifier 16 and the bandpass filter 11 connected. That is, when the attenuator control is performed, the high frequency switch 12 performs communication regardless of transmission / reception in a state where the A terminal and the B terminal of the high frequency switch 12 are connected.

During attenuator control, the signal input from the antenna 10 passes through the bandpass filter 11 and is transmitted to the low noise amplifier 13 due to the isolation effect between the terminals of the high frequency switch 12. Since the high-frequency switch normally obtains isolation of about 20 to 30 dB, the received power input to the high-frequency switch 12 is attenuated by the attenuation amount of the isolation of the high-frequency switch 12 to be low. It is input to the noise amplifier 13.

At this time, since the reception IF signal input to the reception power control circuit 18 is also attenuated, the reception power control circuit 18 is preset when the reception attenuator control signal is output. Attenuator control is performed based on the amount of electric power whose electric power value is attenuated by the amount of attenuation of the high frequency switch 12.

In this embodiment, when the received power is attenuated, the high frequency switch 12 is received at the transmitting side even during reception, and the received power is attenuated by the isolation between the terminals of the high frequency switch 12. Therefore, the attenuator circuit is not required, the cost of parts can be reduced, the circuit can be downsized and simplified, and the high-frequency switch doubles as the attenuator, so the dedicated power supply is not required and the power consumption can be reduced. Is possible.

[0018]

As described above, according to the present invention, the radio frequency switch connected to the antenna switches the connection of the antenna at the time of reception and at the time of transmission, and the reception power control means detects the reception power at the time of reception. When the received power is equal to or higher than the preset power, an attenuator control signal is output, the high frequency switch control circuit switches the high frequency switch to the receiving side and the transmitting side at the time of reception and transmission, and the reception power control means. When the attenuator control signal is input from the, the high frequency switch is switched to the transmission side during reception, and the received power is attenuated by the isolation characteristics of the high frequency switch, so the attenuator circuit is not required and the cost of parts is reduced. It can be realized and the circuit can be miniaturized and simplified, and the high frequency switch doubles as an attenuator. To has the effect of its own power is not required, it is possible to reduce the power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a wireless device having a received power control device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a high frequency switch.

[Explanation of symbols]

 10 Antenna 11 Band Pass Filter 12 High Frequency Switch 13 Low Noise Amplifier 14 Reception Mixer 15 Transmission Mixer 16 Power Amplifier 17 Transmission / Reception Control Circuit 18 Reception Power Control Circuit 19 High Frequency Switch Control Circuit

Claims (3)

[Claims] 1. When the received power input to the antenna is equal to or higher than the preset power, a high frequency switch that switches the connection of the antenna during reception and transmission is switched to the transmission side during reception. Received power control method. 2. A high frequency switch which is connected to an antenna and switches the connection of the antenna during reception and during transmission, and an attenuator control when the received power at the time of reception is detected and the received power is equal to or higher than a preset power. When the reception power control means for outputting a signal and the high frequency switch for reception and transmission are respectively switched to the reception side and the transmission side, and the attenuator control signal from the reception power control means is inputted, the high frequency switch for reception. And a high-frequency switch control circuit for switching to the transmission side. 3. A high frequency switch which is connected to an antenna and has an internal isolation characteristic, and which switches the connection of the antenna at the time of reception and transmission, and the reception power at the time of reception is detected, and the reception power is preset. The received power control means for outputting an attenuator control signal when the power is equal to or higher than the specified power, and the high frequency switch is switched to the receiving side and the transmitting side during reception and transmission, respectively, and the attenuator control signal from the reception power control means is input. Then, at the time of reception, the high-frequency switch is switched to the transmission side, and the reception power from the antenna is attenuated by the isolation inside the high-frequency switch and output to the reception side. Power control device.