US PCS Band Research Articles

High efficiency power amplifier with frequency band selective matching networks

ABSTRACTIn this article, a high efficiency power amplifier (PA) with frequency selective matching networks (MNs) that can provide passband impedance matching as well as suppression of out‐of‐band signals simultaneously is proposed. The proposed frequency selective MN consists of a λ/4 length coupled line, a λ/2 length open step‐impedance resonator stub, and a λ/6 length bias line terminated with a bypass capacitor. For experimental validation, the PA with input and output frequency selective MNs is designed and fabricated for the US PCS band (1.93–1.99 GHz). The measurement results show that the output power and power add efficiency are 43 dBm and 70.3%, respectively, at the center frequency of 1.96 GHz, and the out‐of‐band suppression is higher than 32 dB. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2031–2034, 2015

FULLY EMBEDDED MICRO-TRIPLEXER INTO PCB WITH BaTiO3 FILM

ABSTRACT In this paper, compact passive type triplexer was newly designed and fabricated for US-CDMA handset applications. The newly designed triplexer circuit was comprised of a diplexer, parallel resonant circuit, GPS SAW BPF, and its impedance matching circuit. It was realized by embedding all passive components into multi-layered PCB substrate with BaTiO3 organic composite film. Although the number of passive components to comprise the proposed triplexer and its size were dramatically reduced, its performance characteristics were much improved. It exhibited the measured insertion losses of −0.4 dB, −1.7 dB, and −1.3 dB and the measured isolation characteristics of −10 dB, −24 dB, and −21 dB at DCN, GPS, US-PCS band, respectively. The simulated and measured performance characteristics of fabricated triplexer were well agreed. The fabricated triplexer has a 4.0 × 3.0 mm2 size. Since it has excellent performance characteristics, small size/volume, and low cost, it can be directly applied for US-CDMA handsets.