Nonlinear analysis and optimization of a Distributed Voltage Controlled Oscillator for Cognitive Radio

Abstract

Nonlinear design and optimization of a Distributed Voltage Controlled Oscillator (DVCO) suitable for Cognitive Radio is presented. Harmonic Balance (HB) based optimization techniques have been used to obtain an optimized design of the DVCO aiming at minimizing the output power variation along the frequency band. A prototype has been built showing good agreement with simulation. The measured DVCO has a frequency tuning range from 0.75 GHz to 1.85 GHz, an average dissipation of 59 mW, and an average output power of 5.2 dBm. The average measured phase noise at 1 MHz offset from the carrier across the tuning range is -111.2 dBc/Hz.

Recent Advances on Radio-Frequency Design in Cognitive Radio

“…In [83], a Distributed Voltage-Controlled Oscillator (DVCO) suitable for CR applications is proposed and optimized. To do so, Harmonic Balance (HB) based optimization techniques have been used.…”

Analysis and design of wideband distributed VCOs based on switched-cells tuning technique

“…A DVCO is based on a Distributed Amplifier (DA) operating in the reverse gain mode [9][10][11][12], or in the forward gain mode [13][14][15][16][17][18][19][20]. DVCOs are also known as travelling wave VCOs which belong to the class of wave-based oscillators wherein there are the rotary-travelling wave VCOs (also called closed-loop Distributed VCOs) and standing-wave VCOs [21].…”

Frequency-Tunable and Pattern Diversity Antennas for Cognitive Radio Applications

“…The broad frequency allocation with the variety of the existing standards calls for reconfigurable and frequency agile microwave circuits to pave the way toward reconfigurable radio front-end architectures [1]. The "spectrum overcrowding" arising issue, which is due to the coexisting telecommunication standards in overlapping frequency bands, calls for flexible receiver architectures to efficiently share wireless resources [2]. Cognitive radios are expected to sense the occupancy or target any available channel in the entire spectrum and tolerate interferers at any frequency as well.…”