40 dB-Isolation, 1.85 dB-Insertion Loss Full CMOS SPDT Switch with Body-Floating Technique and Ultra-Small Active Matching Network Using On-Chip Solenoid Inductor for BLE Applications

Abstract

In the IoT/wearable devices, the antenna is shared with the receiver and transmitter of the transceiver. This requires the control of the switch between the antenna and the control circuitry to achieve both low insertion loss and high isolation. This paper presents a low insertion loss and high isolation switch based on Single Pole Double Throw (SPDT) switch for 2.4 GHz Bluetooth low power (BLE) transceiver. The body-floating technique is used to improve the insertion loss’s performance. An ultra-small on-chip matching network with high Q-factor is proposed. The shunt transistors are used as active shunt capacitors that create the active matching network to improve isolation characteristics. The proposed SDPT switch was designed using 55 nm CMOS process with the total area of 110 μm × 210 μm. The insertion loss and isolation characteristics of the proposed SPDT switch observed at 2.4 GHz are 1.85 dB and 40 dB, respectively.