A –90 dBm Sensitivity Wireless Transceiver Using VCO-PA-LNA-Switch-Modulator Co-Design for Low Power Insect-Based Wireless Sensor Networks Serkan Sayilir, Student Member , IEEE ,W i n g - F a i L o k e, Student Member , IEEE , Jangjoon Lee, Student Member , IEEE, Harry Diamond ,M e m b e r ,I E EE

Abstract

This paper presents a wireless transceiver intended for insect-based wireless sens or networks (WSNs). The trans- ceiver utilizes several design tec hniques developed to meet the challenging low power and low size requirements in insect-based WSNs. The techniques include current reuse in the voltage-con- trolled oscillator (VCO) and power ampli fier (PA), fast PLL on/off switching for low-power o n/off keying (OOK) modulation, and switching between transmit and receive (TX/RX) modes without an off-chip switch. Also, the VCO, PA, low noise ampli fier (LNA), OOK modulator, and TX/RX switch are co-designed and integrated into a single block to reduce the system complexity sig- nificantly. The transceiver is designed and fabricated in a 0.13-µm CMOS process. The transmitter provides an output power in the range of –30 dBm to –4.4 dBm while consuming an average power of 1.2 mW to 4.5 mW. The phase locked-loop (PLL) does not use a high-Q external resonator, and its phase noise depends on the PA output power because of the current reuse in the VCO and PA. The PLL phase noise at 1 MHz offset at 2.4 GHz varies from –103.3 dBc/Hz to –116.7 dBc/Hz. The receiver ach ieves a sensitivity of –90 dBm at 1 Mbps data rate for a BER = 0.1%. An example wireless sensor nod e design utilizing the proposed wireless transceiver ach ieves a modest weight of 1 g ram, and a small form factor of 12.5 mm × 12.5 mm.