Return loss

About: Return loss is a research topic. Over the lifetime, 11090 publications have been published within this topic receiving 97603 citations.

Broadband right-angle transition from substrate-integrated waveguide to rectangular waveguide

Abstract: A broadband right-angle transition from a substrate-integrated waveguide (SIW) to a rectangular waveguide (RWG) is proposed. A coupling aperture etched on the broad wall of the SIW and two stepped ridges embedded in the RWG flange are designed for good matching between both waveguides. A Ka-band prototype is designed and fabricated. Good agreement between the measured and simulated results is obtained. The measured results show an insertion loss <;0.55 dB and a return loss below -15 dB from 31.3 to 38.35 GHz. This broadband transition may be used in microwave and millimetre-wave circuits and systems.

A novel tunable transmission line and its application to a phase shifter

Abstract: This letter describes the design of a novel transmission line, where characteristic impedance can be adjusted electronically, and its application to a phase shifter A tunable transmission line enables microwave circuit designers to have flexibility and better return loss which can enhance its tuning range A UHF band distributed analog phase shifter, as well as a tunable transmission line, is presented The characteristic impedance of a fabricated novel transmission line varies from 10 to 695/spl Omega/, which demonstrates its tunability, and the fabricated UHF phase shifter using this novel line shows the possibility of better reflection coefficient and wider tuning range over the conventional capacitively-loaded distributed phase shifter

Ultra-wideband in-phase power divider using stepped-impedance three-line coupled structure and microstrip-to-slotline transitions

Abstract: A compact in-phase power divider utilising a stepped-impedance three-line coupled structure and microstrip-to-slotline transitions is presented. The equivalent circuit of the structure is used to predict the required dimensions for ultra-wideband performance. The length of the structure, excluding the input/output ports needed for the measurements, is around a quarter guided wavelength. The simulated and measured results for the two developed devices indicate equal in-phase power division with less than 0.1 dB and 2° amplitude and phase imbalances, respectively. The return loss at the three ports is more than 15 dB in one prototype, whereas the isolation is more than 13 dB in the other across the band from 3.1 to 10.6 GHz.

Active quasi-circulator realisation with gain elements and slow-wave couplers

Abstract: A microstrip active quasi-circulator is presented using two generic amplifier blocks and two power couplers. The power couplers are parallel-coupled lines with a slow-wave structure in order to improve the isolation between ports of the quasi-circulator. A detailed analytic design procedure is presented for the slow-wave couplers based on the capacitive coupling modelling approach for coupled transmission lines. Experimental results show that the quasi-circulator has an insertion loss between 1 and −2 dB, a return loss better than 11 dB at each of the ports and an isolation better than 20 dB from 1.0 to 3.0 GHz. The input 1 dB compression point is 14 dB m at 2.4 GHz.

Novel Bow-tie–AMC Combination for 5.8-GHz RFID Tags Usable With Metallic Objects

Abstract: A novel combination of coplanar waveguide (CPW)-fed double bow-tie slot antenna and artificial magnetic conductor (AMC), which meets the requirements of a 5.8-GHz SHF RFID tag antenna usable on metallic objects, is presented. The manufactured prototype is characterized in terms of return loss, gain, and radiation pattern measurements in an anechoic chamber, both alone and on a metallic plate.