適用於2.45/3.5 GHz之全相域相移器

Abstract

本論文使用切換式衰減器以及集總元件取代傳輸線，並串接一三位元向量和相移器及一主動全通式相移器，構成一小體積、全相域、高精確度之可調式相移器。此相移器被設計在2.45 GHz及3.5 GHz並以FR4印刷電路板實作，適合WiMax之應用。

In this thesis, full-range phase shifters at 2.45/3.5 GHz are designed and implemented, each of which consists of a lumped 3-bit vector-sum phase shifter and an active all-pass phase shifter. In the 3-bit vector-sum phase shifter, switched attenuators are used to provide attenuation difference with reduced circuit size. The hybrid coupler, Wilkinson dividers, and the 180$^circ$ phase shifter are also designed using lumped inductors and capacitors for size reduction. To reduce the insertion loss and enhance the phase resolution of the phase shifter, an active all-pass phase shifter is cascaded with the 3-bit vector-sum phase shifter. Around 2.45 GHz, measurement results of the 3-bit vector-sum phase shifter show that the standard deviation of phase shift is 9.6 degrees, insertion-loss variation is confined within 4 dB, and the return loss is above 10 dB. The active all-pass phase shifter has gain above 5 dB with phase shift range up to 61 degrees. Around 3.5 GHz, measurement results of the 3-bit vector-sum phase shifter show that the standard deviation of phase shift is 9.9 degrees, insertion-loss variation is confined within 4.7 dB, and the return loss is above 10 dB. The active all-pass phase shifter has gain between 12.7-13.7 dB with phase shift range up to 101 degrees.