A 24 GHz reflective-type phase shifter with constant loss in 0.18 mu m CMOS technology

作者：Askari Mehdi^*; Kaabi Hooman; Kavian Yousef S

来源：AEU-International Journal of Electronics and Communications, 2015, 69(8): 1134-1142.

DOI：10.1016/j.aeue.2015.04.015

• CMOS
• Phase shifter
• Switched attenuator
• Varactor
• Hybrid coupler

With the aim of achieving constant insertion loss, this paper presents the design of a 24 GHz reflectivetype phase shifter (RTPS) integrated with a switched Pi-attenuator for phased.array transmitters. Three RTPS circuits with hybrid coupler and capacitive-type reflective loads are cascaded to obtain required phase-shift. Accumulation-mode MOS (AMOS) varactors are used as reflective loads for phase control. In order to achieve a compact scheme, the hybrid couplers are designed using lumped elements. A switched Pi-attenuator is used in front of the RTPS for gain control. Body switching technique is applied in series switch of the Pi-attenuator to improve its switching performance. Consuming zero DC power, the proposed circuit demonstrates a maximal relative phase-shift range of 185 degrees, a constant insertion loss of 10.7 dB, and a worst-case input return loss better than 15 dB at 24 GHz. The circuit is implemented in a standard 0.18 mu m CMOS technology and the post-layout simulation results are reported.

• 出版日期2015