10-GHz Band Voltage Controlled Oscillator (VCO) MMIC for Motion Detecting Sensors

Abstract

In this work, a voltage controlled oscillator (VCO) monolithic microwave integrated circuit (MMIC) was demonstrated for 10-GHz band motion detecting sensors. The VCO MMIC was fabricated using a $2-{\mu}m$ InGap/GaAs HBT process, and the tuning of the oscillation frequency is achieved by changing the internal capacitance in the HBT, instead of using extra varactor diodes. The implemented VCO MMIC has a micro size of $500{\mu}m{\times}500{\mu}m$, and demonstrates the value of inserting the VCO into a single chip transceiver. The experimental results showed that the frequency tuning characteristic was above 30 MHz, with the excellent output flatness characteristic of ${\pm}0.2dBm$ over the tuning bandwidth. And, the VCO MMIC exhibited a phase noise characteristic of -92.64 dBc/Hz and -118.28 dBc/Hz at the 100 kHz and 1 MHz offset frequencies from the carrier, respectively. The measured values were consistent with the design values, and exhibited good performance.

Fig. 1. Circuit schematics of the voltage controlled oscillator with LC

Fig. 2. The internal equivalent circuit of the InGap/GaAs heterojunction

Fig. 3. The simulation results for the voltage controlled oscillator using the

Fig. 4. Harmonic suppression characteristics above 27 dBc for the

Fig. 5. Output power characteristics of 5.59 dBm for the fabricated voltage

Fig. 6. The characteristics of phase noise versus offset frequencies of the fabricated voltage controlled oscillator MMIC

Fig. 7. Tuning frequency and output power versus tuning voltage of the

Fig. 8. The fabricated voltage controlled oscillator MMIC with the size of 500

Table 1. Electrical performances of the proposed voltage controlledoscillator MMIC