Chao-Hsiung Tseng

TL;DR: In this paper, a low-cost 60 GHz switched-beam patch antenna array with Butler matrix network is developed and experimentally demonstrated, where four rectangular patches fed by inset microstrip lines are connected to the outputs of the Butler matrix for the 60 GHz operation.

TL;DR: In this paper, a rigorous design methodology is developed to design compact planar branch-line and rat-race couplers using asymmetrical T-structures, which is composed of a low-impedance shunt stub and two series high-IMpedance lines with unequal electrical lengths.

TL;DR: In this paper, a coplanar waveguide-fed tapered ring slot antenna for ultrawideband (UWB) applications is presented, which consists of a 50/spl Omega/coplanar Waveguide feeding line, wideband Coplanar W-to-slotline transition, and a pair of curved radiating slots.

TL;DR: In this paper, a compact rat-race coupler is developed using shunt-stub-based artificial transmission lines (SSB ATLs), which can be implemented with a 3.9% circuit size reduction compared to the conventional one.

Abstract: A broadband quadrature power splitter (QPS) is developed using the metamaterial transmission line (MM TL). It consists of a Wilkinson power divider and two phase-adjusting TLs, namely a MM TL and a microstrip (MS). The slope of the phase-response curve of the MM TL is synthesized to be the same as that of the MS along with the 90deg phase increment at two design frequencies. Hence, the broadband quadrature phase difference over the desired frequency range can be obtained. In this letter, the QPS is developed at the center frequency of 2 GHz. Over the frequency range of 1.1-3.5 GHz, an amplitude imbalance of less than 0.9 dB and a phase error of less than plusmn5deg have been experimentally demonstrated.