Bipolar Voltage-controlled Oscillator Research Articles

A Ka -Band Colpitts–Clapp VCO With 30% Tuning Range and High Output Power

This letter presents a systematic design strategy for SiGe bipolar voltage-controlled oscillators (VCOs) with a wide tuning range (TR). As a proof of concept, a Colpitts–Clapp VCO with an ultra-wide continuous TR of 30.2% and center frequency of 35.5 GHz is presented in a 0.13- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> SiGe BiCMOS technology. The measured phase noise of the free-running VCO at 1 MHz offset is better than −99 dBc/Hz over the entire TR. A peak output power of 12.6 dBm is measured with 19.8% of DC-RF efficiency. The VCO exhibits a figure-of-merit (FoMPT) of −193 dBc/Hz. To the best of the authors’ knowledge, the proposed VCO shows the best FoMPT, highest output power and DC-RF efficiency among the reported SiGe VCOs at this frequency range.

Phase Noise Analysis of Bipolar Class-C VCOs With Delay in Oscillator Loop

The expression for phase noise of a bipolar class-C voltage controlled oscillator (VCO) with an ideal delay in the oscillator loop is derived in this paper. The impact of internal device parasitics is then quantified and supported with circuit simulation results. A bipolar class-C VCO is fabricated in a 130-nm BiCMOS technology to validate the analytical predictions. It exhibits a phase noise performance of −112.2 dBc/Hz at 1-MHz offset when running at 19.2 GHz. The tuning range is 7%, and the overall FoM and FoMT are 180.4 dBc/Hz and 177.3 dBc/Hz, respectively.

A 94 GHz Wide Tuning Range SiGe Bipolar VCO Using a Self-Mixing Technique

A self-mixing wide tuning range voltage-controlled oscillator (VCO), using 0.35 μm SiGe bipolar technology, is proposed in this work. The entire circuit consists of a VCO core, a mixer and an emitter coupled differential amplifier. The fundamental and second harmonic signals from the VCO core are used as LO and RF input signals for the mixer circuit, respectively. The mixing product at the third harmonic of the VCO core is selected and amplified, while the low frequency part of the mixing product is suppressed. The simulated harmonic suppression of the third harmonic over fundamental signal is higher than 18 dB. The VCO operates from 91 to 101 GHz with 10.6% tuning range. The measured phase noise at 3 MHz offset is lower than -83 dBc/Hz over the entire frequency band. The VCO occupies 700 × 500 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> die area and consumes 185 mW under 3.5 V dc power supply.

A low-phase-noise voltage-controlled oscillator for 17-GHz applications

A silicon bipolar voltage-controlled oscillator (VCO) for 17-GHz applications is presented. The VCO is composed of a core oscillating at 9GHz followed by a frequency doubler. It adopts a transformer-based topology to obtain both wide tuning range and low noise performance. The VCO exhibits a tuning range of 4.1GHz from 16.4 to 20.5GHz and a phase noise as low as -109dBc/Hz at a 1-MHz frequency offset from a carrier of 18.5GHz.

A low-power low-phase-noise LC VCO with MEMS Cu inductors

A 2-3 GHz CMOS inductance-capacitance (LC) voltage-controlled oscillator (VCO) integrated with high-Q micro-electromechanical systems (MEMS) Cu inductors is reported. While dissipating only 6.3 mW, a phase noise of -121 dBc/Hz at 600 kHz offset from 2.78 GHz carrier is achieved. This MEMS VCO has the largest power-frequency normalized figure-of-merit (12.5 dB) among the Si bipolar and CMOS LC VCOs.

Low phase-noise integrated voltage controlled oscillator design using LTCC technology

This paper describes the design and implementation of a highly integrated voltage controlled oscillator (VCO) module based upon Low-Temperature Co-fired Ceramic (LTCC) packaging technology. The circuit is realized by embedding the strip-line resonator and lumped passives inside a multilayer LTCC substrate. Measurement results of a silicon bipolar VCO circuit operating at 2.4 GHz is shown. The constructed module is compact in size and has good phase noise performance.

A fully-integrated low-power low-noise 2.6-GHz bipolar VCO for wireless applications

The low quality factor of the inductors fabricated in fully-integrated LC tanks results in a poor indirect stability of the oscillators, which are therefore highly sensitive to low-frequency noise and disturbances coupled through substrate and supply lines. The paper addresses the design of a 2-V voltage-controlled oscillator (VCO) at 2.6 GHz fabricated in a Si-bipolar process with f/sub T/ of 20 GHz. The circuit bias and the transistor layout have been specifically optimized to minimize the phase noise degradation due to the intrinsic low indirect stability. A single sideband-to-carrier ratio (SSCR) of -104 dBc/Hz at 100 kHz is demonstrated with less than 14 mW power consumption.

Low-phase-noise low-power IC VCOs for 5-8-GHz wireless applications

A set of fully integrated voltage-controlled oscillators (VCOs) in the 5-8 GHz frequency range has been designed and manufactured in Si bipolar and Si-SiGe-heterojunction-bipolar-transistor technology. A minimum phase noise of -100 dBc/Hz at 100-kHz off carrier was measured for 2-V supply voltage and 16 mW of power consumption. SiGe VCOs give considerably better phase-noise performance than Si bipolar VCOs for the technologies investigated herein, using similar topologies.

A dual mode wideband bipolar microwave transistor voltage‐controlled oscillator design

Results of the design of the microwave bipolar voltage-controlled oscillator (VCO) on coupled transmission lines, tuned by varactors in a wide frequency range, are presented. An opportunity of realization of VCO octave frequency bandwidth is shown in a common emitter bipolar transistor circuit configuration. The large-signal model for bipolar transistor is based on its small-signal Y-parameters and DC characteristics. Results of the theoretical analysis and the numerical calculations of the optimal circuit parameters and the tuning oscillator characteristics are given. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 424–434, 1999

A 108-GHz InP-HBT monolithic push-push VCO with low phase noise and wide tuning bandwidth

This paper reports on what is believed to be the highest frequency bipolar voltage-controlled oscillator (VCO) monolithic microwave integrated circuit (MMIC) so far reported. The W-band VCO is based on a push-push oscillator topology, which employs InP HBT technology with peak f/sub T/'s and f/sub max/'s of 75 and 200 GHz, respectively. The W-band VCO produces a maximum oscillating frequency of 108 GHz and delivers an output power of +0.92 dBm into 50 /spl Omega/. The VCO also obtains a tuning bandwidth of 2.73 GHz or 2.6% using a monolithic varactor. A phase noise of -88 dBc/Hz and -109 dBc/Hz is achieved at 1- and 10-MHz offsets, respectively, and is believed to be the lowest phase noise reported for a monolithic W-band VCO. The push-push VCO design approach demonstrated in this work enables higher VCO frequency operation, lower noise performance, and smaller size, which is attractive for millimeter-wave frequency source applications.

Wide-tuning range Si bipolar VCOs based on three-dimensional MMIC technology

The first completely integrated silicon (Si) bipolar junction transistor (BJT) voltage-controlled oscillators (VCOs), based on three-dimensional (3-D) monolithic-microwave integrated-circuit (MMIC) technology are presented in this paper. The 3-D MMIC technology offers the use of reactive matching in circuit design as well as GaAs MMIC construction and expands the operation frequency of Si MMICs. Two types of VCO MMICs using 0.5-/spl mu/m Si BJTs are presented and demonstrated. Both exhibit a very wide frequency tuning range in the 5- and 6-GHz bands. The former offers the frequency tuning range of 33% using the base-emitter conductance operation of the BJT, which works like a varistor with a large ratio. Furthermore, the oscillation frequency is remarkably linear against the controlled base bias. To confirm the wide-tuning ability of the proposed VCO at higher frequencies, a 7-GHz-band VCO is fabricated on the same Si masterslice array used for the 5-GHz-band VCO. It achieves a 28% tuning range from 5.53 to 7.09 GHz at the collector bias of 2 V. The latter, whose frequency is controlled by a varactor diode, also offers a wide tuning range from 5.15 to 6.75 GHz. The phase noise achieved ranges from -95 dBc/Hz to -117 dBc/Hz at 1-MHz offset frequency over the tuning range of 1.6 GHz (best phase noise performance is -90.5 dBc/Hz at 100 kHz). Measured results show that 3-D MMIC Si VCO's can he developed that yield frequencies above 7 GHz.

A novel heterojunction bipolar transistor VCO using an active tunable inductance

This paper reports on the results of a novel HBT Voltage Controlled Oscillator (VCO) that incorporates a bias-tunable-active inductor. This development benchmarks the first demonstration of a tunable active inductance controlled HBT VCO of this type. The active inductor topology can obtain inductances of up to 10 nH at frequencies up to 10 GHz and can be bias-tuned over a similar range. VCO's were designed at 4 and 10 GHz by implementing different active inductance values. A 29% frequency tuning range from 3.54 to 4.73 GHz was obtained for the 4-GHz design. The output power varied from -1.2 to -0.2 dBm, respectively-less than 1 dB variation over the tuning range. The phase noise is -70 dBc/Hz at 100 kHz offset from the carrier. The new VCO topology can be implemented without the use of backside vias or microstrip-matching components and can be realized in a compact 1.0/spl times/0.7 mm/sup 2/ area. The variable active inductance VCO topology provides a compact, high performance alternative to the analog multi-vibrator oscillator circuit that generally has a smaller tuning capability and worse phase noise performance at microwave frequencies.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Multigigahertz voltage-controlled oscillators in advanced silicon bipolar technology

Relaxation-type monolithic silicon bipolar voltage-controlled oscillators (VCOs) with center frequencies ranging from 1.5 to 5 GHz are described. The maximum oscillating frequency achieved is 7.4 GHz. The VCOs dissipate about 70 mW from a 3.6-V supply, including the output buffer and voltage-to-current converter stages. Two types of on-chip timing capacitor structure and various configurations used in achieving these results are described. A wide tuning range sufficient for covering the normal process tolerances and supply variations expected in a practical environment was achieved. The circuits were fabricated in an advanced 0.8- mu m double-poly self-aligned bipolar technology.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>