A Wideband Contactless and Bondwire-Free MMIC to Waveguide Transition

Abstract

A contactless transition from a high-permittivity microstrip line (r = 9.9) to an air-filled waveguide (WG) has been impedance-matched over a large simulated relative bandwidth of 38% (W-band, 75-110 GHz). The transition couples the EM fields directly from the MMIC's microstrip line via an SIW and an off-chip stub section to a ridge WG section. The novel structure is low loss and suits pick-and-place assembly techniques of mm-Wave MMICs inside metal WGs. The design process is detailed and manufacturing tolerances of the Alumina prototype PCB are discussed. The measured back-to-back structure retains an appreciable insertion loss smaller than 0.8 dB for a single transition and a fractional bandwidth of 28% (72-95 GHz) over which the return loss is greater than 10 dB.

An In-Line Coaxial-to-Waveguide Transition for Q-Band Single-Feed-Per-Beam Antenna Systems

“…This paper proposes an in-line coaxial-to-waveguide transition with a compact geometry to obtain a good match over the whole Q-band (33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50). The aim is to reach the desired matching (typically, at least a return loss (RL) > 20 dB in radioastronomy) without increasing the transverse occupation and limiting the additional components to the strictly necessary, in order to obtain a satisfactory accuracy in the design despite the small operating wavelengths involved.…”

Substrate Integrated Waveguide Filter–Amplifier Design Using Active Coupling Matrix Technique

“…For conventional amplifiers, matching networks are required to transfer the complex impedance of the transistor to 50-Ω. Widely used matching networks include stubs, quarter wavelength transformers, and coupled lines [4]; and specific examples can be found using single coplanar waveguide (CPW) line stubs [5], step ridges [6], and antipodal fin-line arrays [7]. These designs are based on independent transistors and the matching networks, which can suffer from additional loss, extra cost, and large circuit footprint.…”

Octave Bandwidth High-Performance Microstrip-to-Double-Ridge-Waveguide Transition

“…Different structures have been developed in order to improve the wideband response. A contactless transition working in a 28% fractional bandwidth is presented in [8]. Using a ridge structure on the high-permittivity thin-film material, a 37% is demonstrated in [9].…”