Waveguide-based Spatial Power Research Articles

A broadband power-combined amplifier based on multi-stage probe-pair traveling-wave power divider/combiner at Ka-band

A multi-stage traveling-wave waveguide-based spatial power divider/combiner using waveguide-to-microstrip (Wg-Ms) probe-pair coupling structure is proposed and applied to the design of a broadband power-combined amplifier module at Ka-band. An eight-way passive back-to-back power divider-combiner with four-stage Wg-Ms probe-pair transitions has been designed, fabricated, and tested. The measured overall insertion loss is less than 1.5 dB from 28 to 40 GHz, which demonstrates the low-loss performance of the proposed multi-way dividing/combining structure. Based on the passive power divider/combiner, an eight-device power-combined amplifier has been implemented with eight broadband medium power amplifier chips. The measured small-signal gain of the amplifier is more than 18 dB and the output power at 1-dB gain compression (P-1 dB) is higher than 30 dBm in the frequency band of 28–40 GHz. Power combining efficiency is within the range of 76–88%. Furthermore, the performance degradation of the power-combined amplifier due to device failure is also analyzed and tested. The experimental result indicates the reliability of this type of power-combined amplifier.

CHARACTERIZATION AND DESIGN OF MILLIMETER-WAVE FULL-BAND WAVEGUIDE-BASED SPATIAL POWER DIVIDER/COMBINER

The design and implementation of millimeter-wave full-band waveguide-based spatial power divider/combiner are presented in this paper. The divider/combiner is based on a compact waveguide- to-microstrip (Wg-Ms) probe-array transition structure, providing full-band frequency coverage and low insertion loss. E-cient design and analysis method for this type of power divider/combiner is developed using spectral domain method combined with the image theory. Ka-band two-way (1 £ 2) and four- way (2 £ 2) power combining structures are analyzed and optimized. The performances of the both optimized power dividers/combiners are evaluated by experiments in back-to-back conflgurations. The measured overall insertion loss for the 1£2 power divider/combiner is better than 1.4dB over the entire Ka-band, which demonstrates the low-loss performance of the divdier/combiner. The optimized 2 £ 2 power divider/combiner shows a same performance as the 1 £ 2 structure without any degradation in operating bandwidth and insertion loss.

A Waveguide-Based Spatial Power Combining Module at Higher Millimeter-Wave Frequency

This paper presents a waveguide-based spatial power combining module using an improved four-way waveguide-based spatial power dividing/combining network. With a conventional fabrication process, the improved network performs low-loss, broadband and symmetrically power dividing/combining at higher frequency in millimeter wave band, and is easy to be integrated with solid-state high power devices for power combining applications. The corresponding validation is carried out in V-band. The proposed network has a measured loss less than 0.5 dB and exhibits very good amplitude balance and fixed phase relationship in an 8.7 % relative bandwidth, from 55 to 60 GHz. And then, a four-way waveguide-based spatial power combining module is fabricated. The measured power is more than 200 mW in 54.5-61 GHz, and the achieved power combining efficiency is more than 80 % in 54.5-60.5 GHz.

25 W solid state power combining amplifier in Ka-band

This paper presents a new waveguide-based spatial power combining amplifier at millimeter-wave frequency.In this amplifier,a waveguide-microstrip spatial power dividing/combining network is adopted.A four-way broadband low loss symmetrical power dividing/combining is achieved at millimeter-wave frequency with an easy manufacture processing and convenience of integrating solid-state high power devices.The measured output power of this amplifier is more than 43.4 dBm in 29～31 GHz,and the corresponding power combining efficiency is more than 80%.The obtained output power is more than 25 W in 30～30.6 GHz.

Millimetre-wave broadband waveguide-based spatial power-combining amplifier

A millimetre-wave broadband spatial power-combining amplifier has been developed, using a compact waveguide-based spatial power dividing/combining network. In the entire Ka-band, the power dividing/combining network achieves symmetrical four-way power dividing/combining at about 0.2 dB and the power-combining amplifier achieves a combining efficiency of about 72–82%.

Printed antenna design for broadband waveguide‐based spatial power combiners

AbstractDesign of broadband printed antennas, including the finite arrays of interacting patch, U‐strip, U‐slot, and meander slot antennas, are presented for applications in waveguide‐based spatial power combiners operating at X‐band. The effect of several antenna design parameters on antenna bandwidth performance is investigated in this paper. The antenna designs presented show significant advantages in their scattering characteristics compared to rectangular patch and slot antennas traditionally used in spatial power combiners. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 411–415, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10778

MAGNETIC POTENTIAL GREEN'S DYADICS OF MULTILAYERED WAVEGUIDE FOR SPATIAL POWER COMBINING APPLICATIONS - Abstract

Integral equation formulation and magnetic potential Green's dyadics for multilayered rectangular waveguide are presented for modeling interacting printed antenna arrays used in waveguide-based spatial power combiners. Dyadic Green's functions are obtained as a partial eigenfunction expansion in the form of a double series over the complete system of eigenfunctions of transverse Laplacian operator. In this expansion, one-dimensional characteristic Green's functions along a multilayered waveguide are derived in closed form as the solution of a Sturm-Liouville boundary value problem with appropriate boundary and continuity conditions. A method introduced here is based on the transmission matrix approach, wherein the amplitude coefficients of forward and backward traveling waves in the scattered Green's function in different dielectric layers are obtained as a product of transmission matrices of corresponding layers. Convergence of Green's function components in the source region is illustrated for a specific example of a two-layered, terminated rectangular waveguide.

A generalized scattering matrix method using the method of moments for electromagnetic analysis of multilayered structures in waveguide

The method of moments (MoM) in conjunction with the generalized scattering matrix (GSM) approach is proposed to analyze transverse multilayered structures in a metal waveguide. The formulation incorporates ports as an integral part of the GSM formulation, thus, the resulting model can be integrated with circuit analysis. The proposed technique permits the modeling of interactive discontinuities due to the consideration of a large number of modes in the cascade. The GSM-MoM method can be successfully applied to the investigation of a variety of shielded multilayered structures, iris coupled filters, determining the input impedance of probe excited waveguides, and of waveguide-based spatial power combiners.