CN-118353395-B - Multistage ultra-wideband power amplifier

CN118353395BCN 118353395 BCN118353395 BCN 118353395BCN-118353395-B

Abstract

The invention discloses a multistage ultra-wideband power amplifier which comprises a first directional coupler and a second directional coupler, wherein the first directional coupler and the second directional coupler are arranged between output matching of a front-stage power amplifier and input matching of a rear-stage power amplifier, an output end of the output matching is connected with an input end of the first directional coupler, a through end of the first directional coupler outputs a 0-degree through signal, a coupling end of the first directional coupler outputs a coupling signal which is different from the through end by a certain angle, the through end and the coupling end of the second directional coupler are respectively connected with one of two input ends of the second directional coupler, and an output end of the second directional coupler is connected with the input end of the input matching. The invention solves the problem that the matching of the front stage and the back stage of the multi-stage broadband link are mutually influenced, and reduces the difficulty of the inter-stage matching in the broadband matching design.

Inventors

MAO CHAOWU
WAN LIANG
LIU SHENGHOU

Assignees

厦门市三安集成电路有限公司

Dates

Publication Date: 20260505
Application Date: 20240326

Claims (10)

1. The multistage ultra-wideband power amplifier is characterized by comprising a first directional coupler and a second directional coupler, wherein the first directional coupler and the second directional coupler are arranged between a front-stage power amplifier and a rear-stage power amplifier and are used for separating front-stage output impedance and rear-stage input impedance, the output end of the front-stage power amplifier is connected with the input end of the first directional coupler, the first directional coupler branches output signals of the front-stage power amplifier, the through end of the first directional coupler outputs 0-degree through signals, the coupling end of the first directional coupler outputs coupling signals which are different from the through end by a certain angle, the through end of the first directional coupler is connected with one input end of the second directional coupler, the coupling end of the first directional coupler is connected with the other input end of the second directional coupler, the second directional coupler outputs the branched signals of the first directional coupler in a combined way, and the output end of the second directional coupler is connected with the input end of the rear-stage power amplifier.
2. The multi-stage ultra-wideband power amplifier of claim 1, wherein the straight-through and coupled ends of the first directional coupler have a phase difference of 90 degrees, and wherein the two input ends of the second directional coupler have a phase difference of 90 degrees.
3. The multi-stage ultra-wideband power amplifier of claim 1, wherein the first directional coupler and the second directional coupler are each 3dB couplers.
4. The multi-stage ultra-wideband power amplifier of claim 1, wherein the first directional coupler and the second directional coupler each further comprise an isolation terminal, the isolation terminal being load-matched.
5. The multi-stage ultra wideband power amplifier of claim 4, wherein the first directional coupler and the second directional coupler each comprise four ports, wherein a first port of the first directional coupler is an input port, a second port of the first directional coupler is an isolation port, a third port of the first directional coupler is a coupling port, a fourth port of the first directional coupler is a through port, a first port of the second directional coupler is a first input port, a second port of the second directional coupler is a second input port, a third port of the second directional coupler is an isolation port, and a fourth port of the second directional coupler is an output port, wherein the fourth port of the first directional coupler is connected with the second port of the second directional coupler, and the third port of the first directional coupler is connected with the first port of the second directional coupler.
6. The multi-stage ultra wideband power amplifier of claim 4, wherein the first directional coupler and the second directional coupler each comprise four ports, wherein a first port of the first directional coupler is an input port, a second port of the first directional coupler is an isolation port, a third port of the first directional coupler is a coupling port, a fourth port of the first directional coupler is a through port, a first port of the second directional coupler is a first input port, a second port of the second directional coupler is a second input port, a third port of the second directional coupler is an output port, and a fourth port of the second directional coupler is an isolation port, wherein the fourth port of the first directional coupler is connected with the first port of the second directional coupler, and the third port of the first directional coupler is connected with the second port of the second directional coupler.
7. The multi-stage ultra wideband power amplifier of claim 4, wherein the first directional coupler and the second directional coupler each comprise four ports, wherein a first port of the first directional coupler is an isolated port, a second port of the first directional coupler is an input port, a third port of the first directional coupler is a pass-through port, a fourth port of the first directional coupler is a coupled port, a first port of the second directional coupler is a first input port, a second port of the second directional coupler is a second input port, a third port of the second directional coupler is an output port, and a fourth port of the second directional coupler is an isolated port, wherein the fourth port of the first directional coupler is connected with the second port of the second directional coupler, and the third port of the first directional coupler is connected with the first port of the second directional coupler.
8. The multi-stage ultra wideband power amplifier of claim 4, wherein the first directional coupler and the second directional coupler each comprise four ports, wherein a first port of the first directional coupler is an isolated port, a second port of the first directional coupler is an input port, a third port of the first directional coupler is a pass-through port, a fourth port of the first directional coupler is a coupled port, a first port of the second directional coupler is a first input port, a second port of the second directional coupler is a second input port, a third port of the second directional coupler is an isolated port, and a fourth port of the second directional coupler is an output port, wherein the fourth port of the first directional coupler is connected with the first port of the second directional coupler, and the third port of the first directional coupler is connected with the second port of the second directional coupler.
9. The multi-stage ultra-wideband power amplifier of claim 1, wherein the ultra-wideband power amplifier comprises multiple stages, wherein each pre-stage power amplifier and the connected post-stage power amplifier are provided with the first directional coupler and the second directional coupler.
10. The multi-stage ultra wideband power amplifier of claim 1 or 9, wherein the first and second directional couplers are disposed between an output match of a preceding stage power amplifier and an input match of a subsequent stage power amplifier.

Description

Multistage ultra-wideband power amplifier Technical Field The invention relates to the technical field of power amplifiers, in particular to a multistage ultra-wideband power amplifier. Background In order to facilitate large-scale interconnection between people, people and objects, the need to develop an efficient rf front-end transmission system that supports multiple standards is becoming more and more urgent. The rf power amplifier is a key device of the rf link, and determines a plurality of core indexes such as power, efficiency, and the like of the rf link. In order to cover multiple cellular frequency bands of a mobile communication network, and for cost saving purposes, it is necessary to develop ultra wideband power amplifiers with octaves. Besides the mobile communication system, the ultra-wideband power amplifier is one of key devices in electronic warfare and radar systems, and the ultra-wideband radar system can achieve better tracking and positioning of stealth targets so as to achieve more accurate striking. The ultra-wideband radio frequency power amplifier needs to be subjected to wideband matching design, so that the input and output of the power amplifier tube reach optimal impedance matching, and the balance of the overall performance in the wideband is realized. The input impedance and output impedance of the power tube are functions of frequency, while the matching circuit is fixed and does not change with frequency, which creates a difficult problem of broadband matching. Particularly, between two stages of amplifiers, the output impedance of the front stage and the input impedance of the rear stage are simultaneously changed along with the frequency, and the inter-stage matching is difficult in broadband matching design. Referring to fig. 1, a schematic diagram of direct matching of a multi-stage rf power amplifier is shown. The conventional means generally adopts a method of adding an isolator between stages so that matching impedances of the front and rear stages do not interfere with each other, thereby improving the inter-stage matching of the multi-stage amplifier. The disadvantage is that the larger the working bandwidth of the isolator is, the larger the insertion loss is, so that the isolator cannot be used in an ultra-wideband link. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a multi-stage ultra-wideband power amplifier, which combines two directional couplers, separates the output impedance of a front stage from the input impedance of a rear stage by utilizing the excellent wideband performance of the two directional couplers, so that the output impedance and the input impedance of the rear stage are not interfered with each other, realizes the improvement of the inter-stage matching of the ultra-wideband power amplifier, and avoids the problem that the isolator used in the traditional method has larger bandwidth and larger insertion loss so as not to be used in an ultra-wideband link. The technical scheme adopted for solving the technical problems is as follows: The multistage ultra-wideband power amplifier comprises a first directional coupler and a second directional coupler, wherein the first directional coupler and the second directional coupler are arranged between a front-stage power amplifier and a rear-stage power amplifier, the output end of the front-stage power amplifier is connected with the input end of the first directional coupler, the through end of the first directional coupler outputs a 0-degree through signal, the coupling end of the first directional coupler outputs a coupling signal which is different from the through end by a certain angle, the through end of the first directional coupler is connected with one input end of the second directional coupler, the coupling end of the first directional coupler is connected with the other input end of the second directional coupler, and the output end of the second directional coupler is connected with the input end of the rear-stage power amplifier. Preferably, the first directional coupler divides the output signal of the front stage power amplifier, and the second directional coupler combines and outputs the divided signals of the direct end and the coupling end of the first directional coupler. Preferably, the straight end and the coupling end of the first directional coupler have a phase difference of 90 degrees, and the two input ends of the second directional coupler have a phase difference of 90 degrees. Preferably, the first directional coupler and the second directional coupler are 3dB couplers. Preferably, the first directional coupler and the second directional coupler further comprise an isolation end respectively, and the isolation ends are matched with loads. Preferably, the first directional coupler and the second directional coupler comprise four ports, a first port of the first directional coupler is an input end, a second port of the fi