A Dual-Band CMOS Voltage-Controlled Oscillator Implemented With Dual-Resonance LC Tank

Abstract

on-current I c2on is larger than the off-state current I c2off , and a large on-current through the passives causes larger loss. MEASUREMENT RESULTSThe VCOs were designed and fabricated in the TSMC 0.18 lm 1P6M CMOS technology. Figure 3 shows the micrograph of the proposed VCO with a chip area of 0.991 3 0.815 mm 2 including all test pads and dummy metal. Four inductors L are shown. With the supply voltage of V dd 5 0.8 V, the low-/high-band current and power consumption of the core VCO are 6.55/6.85 mA and 5.24/5.48 mW, respectively. Figure 4 shows the tuning ranges of the oscillation frequency while varying V tune . While the control voltage V tune was tuned from 0 to 2.0 V, the VCO operates between 4.5/7.18 and 4.64/7.55 GHz. Figure 4(a) shows the output spectrum at 4.63 GHz, with 211.88 dBm output power. Figure 5(b) shows the output spectrum at 7.46 GHz, with 22.04 dBm output power. The measured high-band/lowband phase noise shown in Figure 6 is 2124.25/2115.84 dBc/ Hz at 1 MHz offset frequency from the center frequency. The measured phase noise shows the 1/Dx 2 -dependence at the offset frequency greater than 1 MHz. and the 1/Dx 3 -dependence at the offset frequency between 100 KHz and 1 MHz. The high-/lowband figure of merit (FOM) is 2194.25/2182.29 dBc/Hz. The FOM is calculated using the equation defined bywhere L{Dx} is the single side-band phase noise measured at Dx offset from x o carrier frequency and P DC is DC power consumption in mW. Table 1 is the performance comparison. CONCLUSIONA novel dual-band standing wave VCO with LH LC network has been proposed and successfully implemented. The dual-band function is based on fundamental and harmonic mode switching using MOSFET as the switching device. The dual-band operation has been obtained by exciting harmonic-mode operation using the MOSFET switch without the need to reconfigure the LH LC network. The VCO generates differential signals in the high-band frequency range of 7.18-7.55 GHz and in the lowband frequency range of 4.5-4.64 GHz. The measured data show the proposed fundamental and high-order harmonic mode switching technique can be used to design a dual-band VCO with good FOM. ACKNOWLEDGMENTThe experimental support of CIC is acknowledged. REFERENCES 1.

A 0.6 V 10 GHz CMOS VCO Using a Negative-Gm Back-Gate Tuned Technique

“…Table II summarizes the overall specifications of the VCO with the prior works [3]- [8]. The proposed circuit can achieve only 0.6 V operation and its is better than those in [3]- [6], [8].…”

A Triple-Band Voltage-Controlled Oscillator Using Two Shunt Right-Handed 4th-Order Resonators

“…In the switching method the resonance frequency of oscillator is modified by adding L and C elements to the tank via MOS switches, which reduces the tuning range and increases phase noise. One alternative uses multi-resonant LC resonator, varactors are used as tuning elements for frequency-band switching and tuning [4]. And various dual-band oscillators [5][6][7] …”

Design of dual‐band colpitts VCO by switched negative resistance shaping

“…One of the challenges in the design of a multiband transceiver RF front‐end is the multiband voltage controlled oscillator (VCO). Recently, research has been carried out to design dual‐band or multiband VCOs using different methods, including switching of the capacitance or inductance in the LC resonant tank [1], [2], active core switching of multiport coupled inductors [3], using a dual‐resonance LC tank [4], and using additive and subtractive coupling of transformer inductances [5].…”