Transformer-Based VCO for W-Band Automotive Radar Applications

Abstract

A transformer-based voltage-controlled oscillator for a W-band frequency-modulated continuous-wave (FMCW) automotive radar application is presented. The design challenges imposed by the millimeter-wave frequency operation were faced through a circuit and layout co-design approach, supported by extensive electromagnetic simulations and accurate analysis of both the start-up condition and the tank quality factor. The oscillator was implemented in a 28-nm fully depleted silicon-on-insulator (SOI) complementary metal–oxide–semiconductor (CMOS) technology. It provided a 37 GHz oscillation frequency with a variation of around 4 GHz, thus achieving a tuning range of 11%. Moreover, a 77 GHz output signal was also delivered, which was extracted as a second harmonic from the input-pair common-mode node. The circuit exhibited low phase noises, whose average performances were −97 dBc/Hz and −121 dBc/Hz at 1 MHz and 10 MHz offset frequencies, respectively. It delivered a 77-GHz output power of −10.5 dBm and dissipated 26 mW with a 1 V power supply. The silicon area occupation was 300 × 135 µm.

CMOS IC Solutions for the 77 GHz Radar Sensor in Automotive Applications

“…This allows setting the bias voltage, VBIAS, to achieve a fair trade-off between the start-up condition and power consumption. The use of a tank transformer simplifies the interconnection of the VCO with the frequency doubler and avoids the parasitic capacitances of an ac-coupling approach based on capacitors [52,53]. It adopts a stacked configuration with octagonal windings, as shown in Figure 14b.…”

Interstacked Transformer Quad-Core VCOs

“…For instance, accuracy and resolution of a radar sensor are strictly related to the phase noise, thus a low-phase-noise oscillator is mandatory to achieve the highest possible target discrimination [1,2]. In this context, LC-resonant VCOs are highly preferred at the cost of a large silicon area consumption, mainly due to the tank inductor [3][4][5][6][7][8]. Traditionally, RF/mm-wave ICs are implemented in BiCMOS or CMOS technologies [9][10][11][12][13][14].…”

Simple multi-band radar signals generation using photon-photon resonance effect in three-section monolithic integrated directly-modulated laser

“…Traditionally, the method of generating FMCW signals mainly based on electrical device, such as voltagecontrolled oscillator (VCO) [5] and direct digital synthesis (DDS) [6]. While, it cannot meet the requirement of high operating frequency, broadband and multi-band in the future.…”