A fully integrated, highly linear CMOS T/R switch for X‐Band phased array radars

Abstract

This paper presents the design and implementation of a single-pole, double-throw transmit/receive (T/R) switch for X-Band (8-12 GHz) phased array radar applications. The T/R switch was fabricated in a 0.25-mm SiGe BiCMOS process and occupies 0.44-mm 2 chip area, including pads. The design focuses on the techniques, primarily, to achieve higher power handling capability (P 1dB ), along with higher isolation and better insertion loss (IL) of the T/R switch. These techniques include resistive-body floating, using on-chip impedance transformation networks and DC biasing of all terminals of the T/R switch. In addition, optimization of transistor widths and parallel resonance technique are used to improve IL and isolation, respectively. All these design techniques resulted in a measured IL of 3.6 dB, isolation of 34.8 dB and IP 1dB of 28.2 dBm at 10 GHz. The return losses at both input and output ports are better than 16 dB from 8 to 12 GHz. To our knowledge, this paper presents the single-ended CMOS T/R switch with the highest IP 1dB , competitive isolation and comparable IL at X-Band, compared to other reported works in the literature and attributed to the unique design methodologies and techniques.

A K‐band high‐gain power amplifier with slow‐wave transmission‐line transformer in 130‐nm RF CMOS

“…Currently, two mm‐wave bands are mainly applied for automotive radar sensors, one is K band at 24 GHz for short‐range applications such as blind‐spot detection and collision avoidance, the other is E band at 77 GHz for long‐range radar communication as adaptive cruise control 1–3 . Attributed to constantly shrinking dimensions of devices, complementary metal oxide semiconductor (CMOS) technology becomes a great competitor of III–V technologies, such as GaAs, InP, and pHEMT, to implement the high performance mm‐wave automotive radars, featuring low cost, low power, compact size, and high integration with analog/digital integrated circuits (ICs) 4,5 …”

Design of high‐isolation and low‐loss single pole double throw switch based on the triple‐coupled transformer for ultra‐wideband phased array systems

“…To improve the power efficiency and sensitivity of transceivers, T/R switches require low insertion loss (IL) and high isolation to avoid RX being interfered by TX. [9][10][11][12] Hence, SPDT switches are key components in mm-wave phased array systems, and SPDT switch design is extremely challenging.…”

A fully integrated high IP1dB CMOS SPDT switch using stacked transistors for 2.4 GHz TDD transceiver applications

“…Mekanand et al (2008) designed a switch by paralleling an NMOS and a PMOS instead of a single MOS to improve the dynamic range in the conducting state, but the IL of the switch was more than 1 dB [14]. Dinc et al (2012) used inductors in parallel to switching transistors in order to form a parallel tank circuit and cancel out some of the transistors' off-state drainsource capacitance [15]. This helped improve the isolation of the switch but in effect it left very high die area because of bulky on-chip inductor.…”