CN110212929B

CN110212929B - A harmonic suppression transmitter

Info

Publication number: CN110212929B
Application number: CN201910435569.3A
Authority: CN
Inventors: 王科平; 周于浩
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2019-05-23
Filing date: 2019-05-23
Publication date: 2021-03-09
Anticipated expiration: 2039-05-23
Also published as: CN110212929A

Abstract

The invention discloses a harmonic suppression transmitter, comprising: a data modulator, a ring oscillator, a phase shifter, a harmonic suppression edge coupler, a power amplifier circuit and an antenna; wherein the data modulator is used for receiving a digital baseband to be transmitted signal, and modulate the signal to be transmitted to generate a low-frequency modulated signal; a ring oscillator is used to output a group of low-frequency signals with equal phase intervals according to the low-frequency modulated signal provided by the data modulator; a phase shifter , used to phase-shift the low-frequency signals to generate the second and third groups of low-frequency signals respectively; the harmonic suppression edge coupler is used to perform edge-coupling on the three groups of low-frequency signals, and output high-frequency steps Wave. The harmonic suppression transmitter, ring oscillator and phase shifter of this embodiment all work at low frequencies, reducing power consumption of the circuit; it can output a staircase wave that is similar to a sine signal, and has the function of harmonic suppression, no need for an inductor-capacitor network, and reduces circuit power consumption. area.

Description

Harmonic suppression transmitter

Technical Field

The invention relates to a transmitter, in particular to a harmonic suppression transmitter, and belongs to the technical field of circuits and systems.

Background

The wireless radio frequency transmitter in the prior art has a front-end circuit composed of a phase-locked loop, a mixer and a power amplifier.

In the working process of the wireless radio frequency transmitter, a high-frequency signal generated by a phase-locked loop and a baseband signal realize a modulation process through a mixer, and a modulated radio frequency signal output by the mixer is transmitted after passing through a power amplifier.

In the above type of radio frequency transmitter, the phase locked loop, the mixer and the power amplifier all operate at high frequencies, resulting in high system power consumption. In addition, the power supply of the relevant components of the baseband requires a power supply current from the power supply to the ground, resulting in a large current consumption of the wireless radio frequency transmitter, which is disadvantageous for the low power consumption performance requirement of the wireless radio frequency transmitter.

A low power Transmitter Based on Injection Locking and edge coupling is shown in Jagdish Pandey et al, entitled "A Sub-100 μ W MICS/ISM Band Transmitter base on Injection-Locking and Frequency multiplexing", in IEEE Journal of Solid-State Circuits, vol.46, No.5, pp.1049-1058, May 2011. Furthermore, once the transmitter frequency changes, the LC network also needs to change accordingly, which inconveniences the wideband application of the transmitter.

In order to eliminate the LC network in the transmitter and to solve the inconvenience in broadband applications, harmonic suppression transmitters, which employ a multiple phase shift synthesis technique, are beginning to be used in wireless communication systems today. However, the oscillator, the phase shifter and the power amplifier in the current harmonic rejection transmitter also operate at high frequencies, which makes the transmitter power consumption high.

Therefore, the wireless radio frequency transmitter in the prior art has the defects of larger power consumption and larger circuit area; the conventional harmonic suppression transmitter does not need an LC network to suppress harmonic components, but still has the problem of high power consumption.

Disclosure of Invention

The invention provides a harmonic suppression transmitter aiming at the problems in the prior art, and the technical scheme can suppress harmonic components, reduce the power consumption of a circuit and reduce the area of the circuit under the condition of not needing an LC network.

In order to achieve the above object, a harmonic suppression transmitter according to a technical solution of the present invention is characterized in that the transmitter includes a data modulator, a ring oscillator, a phase shifter, a harmonic suppression edge coupler, a power amplifier circuit, and an antenna;

the data modulator is used for receiving a digital baseband signal to be transmitted, modulating the signal to be transmitted and generating a low-frequency modulated signal;

the ring oscillator is used for generating a group of N paths of low-frequency signals with equal phase intervals according to the low-frequency modulated signals provided by the data modulator;

the phase shifter is used for performing phase shifting processing on the first group of low-frequency signals to respectively generate a second group of low-frequency signals and a third group of N paths of low-frequency signals;

the harmonic suppression edge coupler is used for respectively carrying out edge coupling on the low-frequency signals and outputting N frequency multiplication step waves;

the power amplification circuit is used for carrying out power amplification on the N frequency multiplication step waves and improving the output power of the transmitter;

the antenna is used for transmitting electromagnetic pulse signals with specific frequency.

As an improvement of the present invention, the phase shifter includes a coarse phase adjusting circuit and a fine phase adjusting circuit; the phase coarse tuning circuit is used for realizing coarse tuning of the phase; the phase fine adjustment circuit is used for realizing accurate adjustment of the phase.

As an improvement of the present invention, the harmonic suppression edge coupler includes an edge coupler 1, an edge coupler 2, and an edge coupler 3, and is configured to perform edge coupling on the first, second, and third groups of low-frequency signals, respectively, and output an N-fold frequency step wave.

As an improvement of the invention, the phase difference of adjacent signals in N low-frequency signals output by the ring oscillator is (180+180/N) °.

As an improvement of the invention, the phase shifter shifts the phase of the first group of N low-frequency signals by (45/N) ° and (90/N) ° respectively to obtain a second group of N low-frequency signals and a third group of N low-frequency signals.

As an improvement of the invention, the harmonic suppression edge coupler has a harmonic suppression function and can output N frequency multiplication step waves, the third harmonic suppression degree and the fifth harmonic suppression degree can reach 47.1dBc and 48.3dBc, the third harmonic suppression degree and the fifth harmonic suppression degree can be respectively improved by 36.5dB and 34.3dB compared with square wave signals, the edge coupler 1, the edge coupler 2 and the edge coupler 3 are all composed of switch MOS tubes, and each edge coupler circuit comprises N paths of input signals and 1 path of output signals.

As an improvement of the invention, the transconductance ratio of the switching MOS tubes in the edge coupler 1, the edge coupler 2 and the edge coupler 3 is equal to

As an improvement of the present invention, the input signals of the edge coupler 1, the edge coupler 2 and the edge coupler 3 are respectively a first group, a second group and a third group of N low-frequency signals; the output ends of the two-phase current sharing circuit are connected in parallel to collect current and share load.

Compared with the prior art, the invention has the advantages that 1) in the technical scheme, the oscillator and the phase shifter both work at low frequency, and the power consumption of the circuit is reduced; the harmonic suppression function is achieved, an on-chip LC network is not needed, and the area of a chip is reduced; 2) the technical scheme adopts the harmonic suppression edge coupler, realizes harmonic suppression while realizing edge coupling frequency multiplication, and reduces the working frequency of an oscillator and a phase shifter, thereby reducing power consumption; while suppressing third and fifth harmonic components, an off-chip LC network is not needed, and off-chip elements are reduced; 3) the technical scheme belongs to non-inductive design, can be applied to a narrow-band system, has applicability to the application of wireless communication systems of various frequency bands, and provides a possible solution for harmonic suppression in a broadband communication system.

Drawings

Fig. 1 is a schematic structural diagram of a harmonic suppression transmitter provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of a phase shifter;

FIG. 3 is a schematic diagram of a harmonic rejection edge coupler;

fig. 4 is a schematic diagram of the operating principle of a single edge coupler (taking N-9 as an example);

fig. 5 is a schematic diagram of a portion of the operating principle of a harmonic rejection edge coupler.

The specific implementation mode is as follows:

for the purpose of enhancing an understanding of the present invention, the present embodiment will be described in detail below with reference to the accompanying drawings.

Example 1: as shown in fig. 1, a harmonic suppression transmitter includes a data modulator, a ring oscillator, a phase shifter, a harmonic suppression edge coupler, a power amplifier circuit, and an antenna;

the phase shifter is used for performing phase shifting processing on the first group of low-frequency signals to respectively generate a second group of low-frequency signals and a third group of N paths of low-frequency signals; the harmonic suppression edge coupler is used for respectively carrying out edge coupling on the low-frequency signals and outputting N frequency multiplication step waves;

the antenna is used for transmitting an electromagnetic pulse signal with a specific frequency;

the phase shifter comprises a phase coarse adjusting circuit and a phase fine adjusting circuit; the phase coarse tuning circuit is used for realizing coarse tuning of the phase; the phase fine adjustment circuit is used for realizing the accurate adjustment of the phase;

the harmonic suppression edge coupler comprises an edge coupler 1, an edge coupler 2 and an edge coupler 3, and is used for respectively carrying out edge coupling on the first, second and third groups of low-frequency signals and outputting N frequency multiplication step waves, and the phase difference of adjacent signals in N paths of low-frequency signals output by the ring oscillator is (180+180/N) °;

the phase shifter respectively shifts the phase of the first group of N paths of low-frequency signals by (45/N) ° and (90/N) ° to obtain a second group of low-frequency signals and a third group of N paths of low-frequency signals;

the harmonic suppression edge coupler has a harmonic suppression function, can output N frequency multiplication step waves, has the third harmonic suppression degree and the fifth harmonic suppression degree reaching 47.1dBc and 48.3dBc, and is respectively improved by 36.5dB and 34.3dB compared with a square wave signal;

the edge coupler 1, the edge coupler 2 and the edge coupler 3 are all composed of switch MOS tubes, and each edge coupler circuit comprises N paths of input signals and 1 path of output signals;

the ratio of transconductance of the switching MOS tubes in the edge coupler 1, the edge coupler 2 and the edge coupler 3 is

The input signals of the edge coupler 1, the edge coupler 2 and the edge coupler 3 are respectively a first group, a second group and a third group of N-path low-frequency signals; the output ends of the two-phase current sharing circuit are connected in parallel to collect current and share load.

The application example is as follows: in order to simplify the circuit, the present embodiment takes N-9 as an example.

Referring to fig. 1, a schematic structural diagram of a harmonic suppression transmitter provided in this embodiment includes: the device comprises a data modulator, a ring oscillator, a phase shifter, a harmonic suppression edge coupler, a power amplifier circuit and an antenna;

the data modulator is used for receiving a digital baseband signal to be transmitted, modulating the signal to be transmitted and outputting a low-frequency modulated signal;

the ring oscillator is used for outputting a group of 9 paths of low-frequency signals with equal phase intervals according to the low-frequency modulated signals provided by the data modulator;

in the harmonic suppression transmitter in this embodiment, a 9-stage ring oscillator is used as a local oscillator to generate 9 paths of low-frequency signals, which are provided to a phase shifter as input signals, and the 9 paths of low-frequency signals are also used as input signals of the edge coupler 1 in the harmonic suppression edge coupler.

In the above harmonic suppression transmitter, a phase difference between adjacent signals among the 9 low-frequency signals output from the ring oscillator is 200 °.

And the phase shifter is used for shifting the phase of 9 paths of signals by 5 degrees and 10 degrees respectively according to the 9 paths of low-frequency signals provided by the ring oscillator to obtain a second group of low-frequency signals and a third group of N paths of low-frequency signals which are used as input signals of the edge coupler 2 and the edge coupler 3 respectively.

As shown in fig. 2, which is a schematic structural diagram of a phase shifter in the harmonic suppression transmitter of this embodiment, the phase shifter includes a coarse phase adjusting circuit and a fine phase adjusting circuit, which respectively implement coarse adjustment and fine adjustment of a signal phase. The structural schematic diagram of the harmonic suppression edge coupler is shown in fig. 3, and the harmonic suppression edge coupler is composed of an edge coupler 1, an edge coupler 2 and an edge coupler 3; the structures of the transistors are the same and are all composed of switch MOS tubes, and the transconductance ratio of the switch MOS tubes is

Each edge coupler circuit comprises N paths of input signals and 1 path of output signals, wherein the input signals of the edge coupler circuits are respectively N paths of low-frequency signals of a first group, a second group and a third group; the output ends of the two-phase current sharing circuit are connected in parallel to collect current and share load. A single edge coupler maySo as to synthesize N paths of low-frequency signals into N times of high-frequency square wave output signals. The working principle of the edge coupler is schematically shown in fig. 4 (taking N ═ 9 as an example). The working principle of the harmonic-suppression edge coupler is shown in fig. 5 (V in the figure)_NRepresenting the output signal of a harmonic-rejection edge coupler), V)_NThe suppression degree of third harmonic and fifth harmonic in the signal frequency spectrum can reach 47.1dBc and 48.3dBc, and is respectively improved by 36.5dB and 34.3dB compared with a square signal.

As can be seen from the above description, the harmonic suppression transmitter of the embodiment adopts the harmonic suppression edge coupler, achieves harmonic suppression while achieving edge coupling frequency multiplication, and reduces the operating frequencies of the oscillator and the phase shifter, thereby reducing power consumption and improving the performance of the transmitter; and when the harmonic component is suppressed, an LC network is not needed, the circuit area is reduced, the circuit structure is simple, and the circuit design and the implementation of the harmonic suppression transmitter are facilitated. The technical scheme belongs to non-inductive design, can be applied to a narrow-band system, has applicability to the application of wireless communication systems of various frequency bands, and provides a possible solution for harmonic suppression in a broadband communication system. It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and all equivalent modifications and substitutions based on the above-mentioned technical solutions are within the scope of the present invention as defined in the claims.

Claims

1. A harmonic suppression transmitter, characterized in that the transmitter comprises a data modulator, a ring oscillator, a phase shifter, a harmonic suppression edge coupler, a power amplifier circuit and an antenna;

The data modulator is used to receive the digital baseband signal to be transmitted, and modulate the to-be-transmitted signal to generate a low-frequency modulated signal;

The ring oscillator is used to generate a group of N-channel low-frequency signals with equal phase intervals according to the low-frequency modulated signal provided by the data modulator; wherein, N≥3, and N is an odd number;

The phase shifter is used to perform phase-shift processing on the first group of low-frequency signals to generate the second group and the third group of N-channel low-frequency signals respectively;

The harmonic suppression edge coupler is used for edge coupling of all low-frequency signals respectively, and outputs an N-multiplier ladder wave;

The power amplifier circuit is used to amplify the power of the N-multiplied ladder wave to improve the output power of the transmitter; the antenna is used to transmit electromagnetic pulse signals of a specific frequency.

2 . The harmonic suppression transmitter according to claim 1 , wherein the phase shifter comprises a phase coarse adjustment circuit and a phase fine adjustment circuit; wherein, the phase coarse adjustment circuit is used to realize the coarse phase adjustment circuit. 3 . adjustment; the phase fine adjustment circuit is used to realize precise adjustment of the phase.

3. The harmonic suppression transmitter according to claim 2, wherein the harmonic suppression edge coupler comprises an edge coupler 1, an edge coupler 2 and an edge coupler 3, which are used to The first, second, and third groups of low-frequency signals are edge-coupled, respectively, and output N-multiplier ladder waves.

4 . The harmonic suppression transmitter according to claim 2 , wherein the phase difference between adjacent signals in the N channels of low-frequency signals output by the ring oscillator is (180+180/N)°. 5 .

5. The harmonic suppression transmitter according to claim 4, characterized in that, after the phase shifter shifts the phases of the first group of N-way low-frequency signals by (45/N)° and (90/N)°, respectively, Obtain the second and third groups of N-channel low-frequency signals.

6 . The harmonic suppression transmitter according to claim 5 , wherein the harmonic suppression edge coupler has a harmonic suppression function, and can output an N-fold frequency step wave, and the third and fifth harmonic suppression degrees are adjustable. 7 . It reaches 47.1dBc and 48.3dBc, which are 36.5dB and 34.3dB higher than the square wave signal respectively.

7. The harmonic suppression transmitter according to claim 6, wherein the edge coupler 1, the edge coupler 2 and the edge coupler 3 are all composed of switch MOS transistors, and each edge coupler circuit comprises N input signal, 1 output signal.

8. The harmonic suppression transmitter according to claim 7, wherein the ratio of the transconductances of the middle switch MOS transistors of the edge coupler 1, the edge coupler 2 and the edge coupler 3 is:

9. The harmonic suppression transmitter according to claim 8, wherein the input signals of the edge coupler 1, the edge coupler 2 and the edge coupler 3 are respectively the first group, the second group and the third group A group of N low-frequency signals; its output ends collect current through a parallel structure to share the load.