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CN-122026810-A - Push-push type oscillator of substrate integrated balance filtering power division network

CN122026810ACN 122026810 ACN122026810 ACN 122026810ACN-122026810-A

Abstract

The invention provides a push-push type oscillator of a substrate integrated balance filtering power division network, which comprises two sub-oscillators working at fundamental frequency and a balance substrate integrated waveguide filtering power divider, wherein the filtering power divider consists of a plurality of inter-stage coupled substrate integrated waveguide resonant cavities and is provided with a pair of differential input ports and two pairs of differential output ports, and the functions of bandpass filtering and power distribution are simultaneously realized in the same physical structure, namely, the frequency of the fundamental frequency signal is selected to stabilize the oscillation frequency, and the frequency-selected fundamental frequency signal is distributed to the feedback loops of the two sub-oscillators in equal amplitude and opposite phase. The filter power divider adopts a single-layer low-loss high-frequency dielectric substrate, a coupling window of the filter power divider introduces a transmission zero point to enhance out-of-band rejection, and a group delay peak value is formed at the edge of a passband to reduce phase noise. The invention realizes miniaturization, low loss, low phase noise and high harmonic suppression, and is suitable for wireless communication and radar systems.

Inventors

  • YANG BINQI
  • ZHOU XIAOHUI
  • ZHOU KE

Assignees

  • 南京软赫电子科技有限公司

Dates

Publication Date
20260512
Application Date
20260331

Claims (10)

  1. 1. A push-push oscillator of a substrate integrated balanced filtering power division network, comprising: Two sub-oscillators working at a fundamental frequency, the sub-oscillators outputting an inverted fundamental frequency signal and an in-phase second harmonic signal; The balanced substrate integrated waveguide filter power divider (100), the filter power divider (100) is composed of a plurality of substrate integrated waveguide resonant cavities and is integrally provided with: A differential input port connected with the output ends of the two sub-oscillators and used for receiving the inverted fundamental frequency signals; at least two differential output ports respectively connected with the feedback loops of the two sub-oscillators and used for distributing the fundamental frequency signals subjected to frequency selection to the sub-oscillators; The balanced substrate integrated waveguide filter power divider (100) integrates the band-pass filtering and power distribution functions, an input end of the balanced substrate integrated waveguide filter power divider receives the inverted fundamental frequency signals of the sub-oscillators, and the inverted fundamental frequency signals are distributed to feedback loops of the two sub-oscillators in constant amplitude and opposite phase through an output end after frequency selection, so that frequency stability and signal feedback are realized.
  2. 2. The push-push oscillator of claim 1, wherein the balanced substrate integrated waveguide filter power divider (100) comprises a plurality of inter-stage coupled substrate integrated waveguide resonators, each resonator being surrounded by metallized vias (150) extending through a dielectric substrate (160) and connecting top and bottom metal layers to form a resonator wall.
  3. 3. A push-push oscillator according to claim 2, characterized in that inter-stage coupling is achieved between the substrate integrated waveguide resonators through coupling windows, and at least one coupling window is arranged to introduce a transmission zero.
  4. 4. The push-push oscillator according to claim 1, wherein an isolation resistor is loaded between differential output ports of the balanced substrate integrated waveguide filter power divider (100) for improving isolation between the output ports.
  5. 5. A push-push oscillator according to claim 4, characterized in that the isolation resistor is a 100 Ω chip resistor.
  6. 6. A push-push oscillator according to claim 1, characterized in that each sub-oscillator comprises a transistor and a bias circuit, a matching network and a delay line connected thereto for forming together with the balanced substrate integrated waveguide filter power divider (100) a feedback loop for a fundamental frequency signal.
  7. 7. The push-push oscillator of claim 6, wherein the matching network comprises an input matching network (310) and an output matching network (320), and a blocking capacitor (360) is provided in the input matching network and the output matching network.
  8. 8. The push-push type oscillator according to claim 6, wherein the two sub-oscillators respectively output signals including an inverted fundamental frequency component and an in-phase second harmonic component, and the two signals are superimposed by a power divider (280) to output a signal having a main frequency of the second harmonic from the output port (300).
  9. 9. The push-push type oscillator according to claim 1, wherein the balanced type substrate integrated waveguide filter power divider (100) adopts a single-layer dielectric substrate structure, and the dielectric substrate (160) is a low-loss high-frequency plate suitable for microwave millimeter wave frequency band operation.
  10. 10. The push-push oscillator of claim 9, wherein the dielectric substrate (160) is Rogers RT/Duroid 5880, with a thickness of 0.508mm, a dielectric constant of 2.2, and top and bottom metal layers with a thickness of 0.035mm.

Description

Push-push type oscillator of substrate integrated balance filtering power division network Technical Field The invention relates to the technical field of microwave oscillators, in particular to a push-push type oscillator of a substrate integrated balance filter power division network. Background With the development of modern wireless communication systems, millimeter wave oscillators with high performance and high integration have become a research hotspot. Push-push oscillators are widely used because they can effectively suppress fundamental frequency and odd harmonics and increase the output power of the second harmonic. However, the conventional push-push type oscillator has the problems that the frequency selection and the power division network are separated in the series feedback structure, so that the size is large, the insertion loss is high, and the parallel feedback structure is improved, but has the defects of non-ideal phase noise and the like. In the millimeter wave frequency band, the traditional microstrip resonator has large loss, and the dielectric resonator and the metal waveguide are difficult to integrate with a planar circuit. Substrate Integrated Waveguide (SIW) technology has been attracting attention because of its high quality factor, low loss, and easy integration, and SIW-based filters and power splitters have been designed in a variety of ways. For example, CN110350278B discloses a SIW power divider with a third-order bandpass response, but it is a passive device design, not combined with an active oscillator, and is a single-ended unbalanced structure, and cannot achieve common-mode rejection and signal phase processing required by a push-push type oscillator. CN114843729B proposes an unbalanced-to-balanced SIW filter power divider, which solves the problem of single-ended-to-differential conversion, but is still a passive device, and is not optimized for the group delay characteristics required by the oscillator, and also cannot realize the fundamental frequency inverse distribution and second harmonic synthesis of the push-push type oscillator. In terms of oscillator application, CN103531878B discloses a push-push and push-pull dual output SIW oscillator, but its frequency selection and power division functions are completed by two independent devices of resonant cavity and magic T, and the integration level is low, and the filtering characteristics are lacking, and the phase noise and harmonic suppression capability are limited. CN116388693a proposes a low-phase noise oscillator based on a multimode SIW filter power divider, but it is a single loop feedback structure, outputs a fundamental frequency signal, does not adopt differential balance design, and has poor common mode rejection and port isolation. Therefore, there is a need for a push-push oscillator design that integrates filtering and power splitting functions, has a differential balance structure, and is optimized for oscillator requirements, to achieve a combination of low phase noise, high harmonic rejection, and miniaturization. Disclosure of Invention In order to solve the problems of complex structure, large size, non-ideal phase noise and the like of the traditional push-push type oscillator and realize the technical effects of low phase noise, high harmonic suppression degree and compact structure, the invention provides a push-push type feedback type oscillator with low phase noise based on a balanced substrate integrated waveguide filter power divider. The invention provides a push-push type oscillator of a substrate integrated balance filtering power division network, two sub-oscillators working at fundamental frequency, wherein the sub-oscillators output inverted fundamental frequency signals and in-phase second harmonic signals; the balanced substrate integrated waveguide filtering power divider is composed of a plurality of substrate integrated waveguide resonant cavities and is integrally provided with: A differential input port connected with the output ends of the two sub-oscillators and used for receiving the inverted fundamental frequency signals; at least two differential output ports respectively connected with the feedback loops of the two sub-oscillators and used for distributing the fundamental frequency signals subjected to frequency selection to the sub-oscillators; the balanced substrate integrated waveguide filter power divider integrates the functions of band-pass filtering and power distribution, the input end of the balanced substrate integrated waveguide filter power divider receives the inverse fundamental frequency signals of the sub-oscillators, and the inverse fundamental frequency signals are distributed to feedback loops of the two sub-oscillators in constant amplitude and inverse phase through the output end after frequency selection, so that frequency stability and signal feedback are realized. Compared with the prior art, the invention has the beneficial effects that: The