A 5-Bit X-Band GaN HEMT-Based Phase Shifter

Hsien-Chin Chiu,Li-Chun Chang,Chun-Ming Chen,Hsuan-Ling Kao

doi:10.3390/electronics10060658

Hsien-Chin Chiu, Li-Chun Chang + Show 2 more

Open Access

https://doi.org/10.3390/electronics10060658

Copy DOI

Abstract

In this study, we propose a 5-bit X-band gallium nitride (GaN) high electron mobility transistor (HEMT)-based phased shifter monolithic microwave integrated circuit for a phased-array technique. The design includes high-pass/low-pass networks for the 180° phase bit, two high-pass/bandpass networks separated for the 45° and 90° phase bits, and two transmission lines based on traveling wave switch and capacitive load networks that are separated for the 11.25° and 22.5° phase bits. The state-to-state variation in the insertion loss is 11.8 ± 3.45 dB, and an input/output return loss of less than 8 dB was obtained in a frequency range of 8–12 GHz. Moreover, the phase shifter achieved a low root mean square (RMS) phase error and RMS amplitude error of 6.23° and 1.15 dB, respectively, under the same frequency range. The measured input-referred P1dB of the five primary phase shift states were larger than 29 dBm at 8 GHz. The RMS phase error and RMS amplitude error slightly increased when the temperature increased from 25 to 100 °C. The on-chip phase shifter exhibited no dc power consumption and occupied an area of 2 × 3 mm2.

Highlights

The phased-array technology has been developed for decades in military and radar applications [1,2,3]
To improve the performance of the phase shifter, this paper reports an X-band 5-bit phase shifter fabricated using a 0.25 μm AlGaN/gallium nitride (GaN) high electron mobility transistor (HEMT)-on-SiC process
The proposed 5-bit phase shifter consists of high-pass/low-pass networks, two high-pass/bandpass networks, and two transmission lines based on traveling wave switch and capacitive load networks, which are arrangement for the 180◦, 45◦ and 90◦, and 11.25◦ and 22.5◦-phase bits, respectively

Summary

Introduction

The phased-array technology has been developed for decades in military and radar applications [1,2,3]. Because a large amount of phase shifters are required for a phase array system, a GaN high electron mobility transistor (HEMT)-based monolithic microwave integrated circuit (MMIC) is a good candidate to provide single-chip transmitter/receiver modules with high-power handling capability and good reliability [11,12,13]. The proposed 5-bit phase shifter consists of high-pass/low-pass networks, two high-pass/bandpass networks, and two transmission lines based on traveling wave switch and capacitive load networks, which are arrangement for the 180◦, 45◦ and 90◦, and 11.25◦ and 22.5◦-phase bits, respectively.

Results

Conclusion