Push-pull power amplifier integrated with microstrip leaky-waveantenna

An X-band active integrated antenna push-pull power amplifier is presented that uses a dual feed microstrip leaky-wave antenna for both out-of-phase power combining and second harmonic tuning. This novel structure results in a compact and high efficiency power amplifier design. At the operating frequency of 8.7 GHz. A maximum measured PAE of 54% at an output power of 38.1 dBm has been achieved     

V-Band GaAs pHEMT Cross-Coupled Sub-Harmonic Oscillator

A$V$-band cross-coupled sub-harmonic injection-locked oscillator has been designed and fabricated using 0.15-$mu$m GaAs pHMET technology. Based on the known harmonic injecting circuit topology, this oscillator was designed by a differential output approach, a low-$Q$microstrip-line resonator, and a current mirror, which has a free-running oscillation frequency around 60GHz with a tuning range of 2.5GHz (from 57.8GHz to 60.3GHz). The maximum single-end output power is 3.8dBm with a dc dissipation of 225mW under a$-$3V supply voltage. Within the input matching network for second (30GHz) and fourth (15GHz) sub-harmonic signals injection, it demonstrates the maximum locking ranges close to 120MHz and 30MHz, respectively.     

Active inverted stripline circular patch antennas for spatial powercombining

An active antenna configuration is proposed for spatial-power-combining applications. The active patch antenna uses an inverted stripline topology to take advantage of several features. These features include avoiding drilling through the circuit substrate to insert the diode and the use of air within the resonant cavity to reduce loss. The inverted substrate serves as a radome for hermetic sealing. The active antenna and housing can be fabricated in modular form for reduced cost and easy replaceability of devices. The active inverted stripline patch antenna exhibits a much cleaner spectrum and greater stability than previously reported active antennas. The fixture serves as a ground plane, heat sink, and support in an active planar array or as a mirror in a quasi-optical power-combining resonator. A single active antenna operating at 9.23 GHz exhibited a 16-MHz locking bandwidth at 30-dB locking gain. Power-combining efficiencies of over 89% have been demonstrated for a four-element square array that maintained injection-locking and power-combining over a 60-MHz bias tuned bandwidth. Similarly, a four-element diamond array showed over 86% combining efficiency and 50-MHz bias tuned bandwidth. Beam steering was demonstrated by varying bias voltage to the individual antenna elements of the square array     

Experiments on injection locking of active antenna elements foractive phased arrays and spatial power combiners

Two types of active antenna elements have been studied experimentally. One type uses a microstrip antenna with an active device mounted directly on the antenna. The other uses an active device coupled to a microstrip patch antenna through an aperture. Microstrip active antenna elements and two-element arrays have been demonstrated for both types of circuits. Injection locking of the antenna elements has been achieved through space and mutual coupling. The circuit Q factor was calculated based on the locking gain and the locking bandwidth. The power output from two elements has been successfully combined in free space with a combining efficiency of over 90%. For a single active antenna with a Gunn diode mounted directly on the patch, an electronic tuning range exceeding 9% has been achieved by varying the DC bias. The results should have many applications in low-cost active arrays, active transmitters, and spatial power combiners     

U-band shield suspended-stripline Gunn DRO and VCO

A millimeter-wave IC dielectric resonator oscillator (DRO) is proposed. Equations that give the resonant frequency of the dielectric resonator DR in suspended stripline (SSL) are derived. A U-band voltage-controlled oscillator (VCO) with varactor tuning also has been developed. The Gunn diode and varactor used in both of the oscillators are commercially available packaged devices. Restrictions on the performance of the oscillators imposed by packaged and mounted networks and the self-characteristics of the solid-state devices have been analyzed. An electronic tuning range greater than 1000 MHz with an output power exceeding 15 dBm across the bandwidth in the 53-GHz region has been realized for the SSL VCO. An SSL DRO with an output power of more than 17 dBm and a mechanical tuning range of 1.5 GHz in the 54-GHz region has been achieved     

Wideband Design of the Fully Integrated Transmitter Front-End With High Power-Added Efficiency

A novel approach to enhance power-added efficiency (PAE) bandwidth and transmitting power bandwidth of the fully integrated transmitter front-end is proposed. To obtain these characteristics, a wideband multifunctional antenna operating as an output matching load of the power transistor and harmonic tuning circuits, as well as a radiator, is designed and fully integrated with a power transistor. Therefore, the wideband direct integration between the output of the power transistor and input of the antenna can be achieved without any impedance transformers. Under the condition of PAE over 50% and transmitting power within 3 dB for the peak transmitting power at the operating band, the measured PAE bandwidth and transmitting power bandwidth are 930 MHz (from 4.9 to 5.83 GHz) and 1030 MHz (from 4.8 to 5.83 GHz), respectively. About a half size is also obtained compared with the conventional wideband class F active antenna for high PAE, and the second and third harmonic radiations of the proposed structure for the normalized peak power of the fundamental frequency are measured less than -30 and -40 dB in all directions, respectively     

A 50-GHz silicon IMPATT diode oscillator and amplifier

Recent experimental observations on a silicon impact avalanche transit-time diode oscillator and amplifier CW-operated at 50 GHz are presented. 1) CW oscillation power of 100 mW was obtained at an overall efficiency of 2 percent. The oscillation frequency was continuously tunable over a 1.3-GHz range by a sliding short. 2) Phase-locking has been achieved with a maximum normalized gain-bandwidth product of 0.1. The minimum locking signal power required for a 500-MHz locking bandwidth was 20 dB below the oscillator output. 3) Electronic tuning of the oscillator frequency was demonstrated by placing a millimeter-wave varactor diode in the tuning circuit. The output frequency versus the bias voltage on the varactor diode was linear with maximum frequency deviation of 300 MHz. Frequency modulation of the oscillator by driving the varactor with a sinusoidal source was obtained at a modulation frequency of 50 MHz. 4) Stable amplification with 13-dB gain was obtained, centered at 52.885 GHz with a 3-dB bandwidth of 1 GHz. The maximum output power obtained was 16 mW. Higher gain of about 17 dB was obtained at a reduced bandwidth. The noise figure of the amplifier was 36 dB. Equivalent circuits for the oscillator and the amplifier are derived. The calculated results agree reasonably well with the experimental observations.     

A 16 element quasi-optical FET oscillator power combining arraywith external injection locking

The authors present analysis, design and experimental results of a 16 element planar oscillator array for quasi-optical power combining. Each element in the array consists of a single FET oscillator with an input port for injection of the locking signal and an output port which is connected to a patch radiator. The array is synchronized using a 16-way power dividing network which distributes the locking signal to the oscillating elements. The array is constructed using a two-sided microstrip configuration, with the oscillators and feed network on one side of a ground plane, and the patch radiators on the opposite side. An effective radiated power (ERP) of 28.2 W CW with an isotropic conversion gain of 9.9 dB was measured at 6 GHz. For an injected power of 10.3 dBm, a locking range of 453 MHz at a center frequency of 6.015 GHz was obtained; a bandwidth of 7.5%. Because of the simple nature of the individual oscillator elements, this approach is well suited to MMIC implementation     

Frequency conversion with gain through sideband locking of an IMPATT diode oscillation

An up-converter with gain and stabilized frequency can be realized through the sideband locking of an IMPATT oscillator. An up-converter with a gain of 13.3 dB (microwave to microwave) and an output power of 13.3 dBm over the bandwidth 30 MHz is realized and operated at 10.18 GHz.     

V-band harmonic injection-locked frequency divider using cross-coupled FETs

A V-band 1/2 frequency divider is developed using harmonic injection-locked oscillator. The cross-coupled field effect transistors (FETs) and low quality-factor microstrip resonator are employed as a wide-band oscillator to extend the locking bandwidth. The second harmonic of free-running oscillation signal is injected to the gates of cross-coupled FETs for high-sensitivity superharmonic injection locking. The fabricated microwave monolithic integrated circuit frequency divider using 0.15-/spl mu/m GaAs pHEMT process showed a maximum locking range of 7.4 GHz (from 65.1 to 72.5 GHz) under a low power dissipation of 100 mW. The maximum single-ended output power was as high as -3 dBm.     

A dual-gate 2nd/3rd-order subharmonic injection-locked oscillator in GaAs PHEMT

A dual-gate subharmonic injection-locked oscillator (SILO) has been designed and fabricated in 0.5 μm GaAs PHEMT process for millimeter-wave communication applications. Specifically, this study proposes a dual-gate circuit topology to achieve a high-frequency oscillator with a large output signal power. The proposed dual-gate transistor also performs a wideband negative resistance characteristic by which the self-oscillation frequency can easily be determined with a proper resonator. The measured self-oscillation frequency of the proposed SILO is approximately 49 GHz, and the frequency tuning range is adjustable from 48.7 GHz to 49.7 GHz with an output power of 8 dBm. By injecting a 2nd-order (~24.5 GHz) subharmonic signal into the dual-gate SILO, the maximum locking range of 5.6 GHz can be approached at an input power of 11 dBm without any self-oscillation frequency tuning. With changing the input frequency to be a 3rd-order subharmonic injection (~16.3 GHz), an output locking range of 2.9 GHz also can be achieved. The measured phase noises of the output signals from 2nd- and 3rd-order subharmonic injections are −101 and −100 dBc/Hz, respectively, at 100-kHz offset frequency.     

A 2.7-V 1.8-GHz fourth-order tunable LC bandpass filter based on emulation of magnetically coupled resonators

A low-voltage fourth-order RF bandpass filter structure based on emulation of two magnetically coupled resonators is presented. A unique feature of the proposed architecture is using electric coupling to emulate the effect of the coupled inductors, thus providing bandwidth tuning with small passband ripple. Each resonator is built using on-chip spiral inductors and accumulation-mode pMOS capacitors to provide center frequency tuning. The filter has been implemented in HP 0.5-/spl mu/m CMOS process and occupies an area of 0.15 mm/sup 2/. It consumes 16 mA from a single 2.7-V supply at a center frequency of 1.84 GHz and a bandwidth of 80 MHz while providing a passband gain of 9 dB and more than 30 dB of image attenuation for an IF frequency of 100 MHz. The measured output 1-dB compression point and output noise power spectral densities are -16 dBm and -137 dBm/Hz, respectively. This results in a 1-dB compression dynamic range of 42 dB. The filter minimum power supply voltage for proper operation is 2 V. The chip experimental results are in good agreement with theoretical results.     

单片低噪声HBT VCO

报道一组单片HBTVCO电路的设计、制作及其测试结果。电路采用HBT作为有源器件，PN结二极管作为变容管。S波段单片VCO的输出功率为0dBm，调谐范围100MHz，在载波频率2．84GHz处，相位噪声为－80dBc／Hz＠100kHz。以C波段单片HBTVCO的输出功率为－10dBm。这些结果表示HBT在微波与毫米波振荡器运用中具有较好的低相位噪声特性。     

A low phase noise silicon 18-GHz push-push VCO

The design and measurement of a push-push voltage controlled oscillator (VCO) at 18.66-18.3 GHz are presented in this paper. The circuit includes two packaged silicon transistors (Siemens BFP 540F) and a microstrip resonator tuned by two GaAs varactor diodes (M/A-COM ML46580). A 360-MHz tuning range is obtained with an output power of 0-3.1 dBm. The fundamental rejection is around 17 dB for a wide range of collector bias current. The phase noise is below -103 dBc/Hz at 100-kHz offset and below -122 dBc/Hz at 1 MHz for the entire tuning bandwidth.     

基于新颖调谐谐振器的低相噪VCO设计

介绍了一种采用新颖谐振器的低相位噪声窄带压控振荡器(VCO)的设计方法。该谐振器采用源与负载横向交叉耦合结构,形成一个传输零点,提高了谐振器的Q值。该谐振器通过弱耦合与变容二极管连接,从而实现电压控制滤波器通带中心频率调谐。利用该谐振器设计了一个窄带VCO,并在先进设计系统(ADS)软件里仿真验证。该VCO中心频率6.15 GHz,在调谐电压从0到15 V的范围内调谐带宽60 MHz,相位噪声在整个调谐范围内优于-132 dBc/Hz@1MHz,输出功率为8.4 dBm,功率平坦度±0.1 dBm。     

基于CMOS工艺的太赫兹振荡器

在太赫兹频段,无源器件电容电感的品质因数低、电路的寄生参数以及MOS管的截止频率影响使太赫兹振荡器电路难以实现高功率输出。提出一种300 GHz可调谐振荡器,首先,采用改进的交叉耦合双推(Push-Push)振荡器结构,通过输出功率叠加的方法输出二次谐波300 GHz信号,增加了振荡器的输出功率并突破了MOS管截止频率,并通过增加栅极互连电感增加输出功率。其次,太赫兹振荡器摒弃传统片上可变电容调谐的方式,通过调节MOS管衬底电压改变MOS管的栅极寄生电容实现频率调谐,避免太赫兹频段引入低Q值电容,进一步增加了输出功率。提出的太赫兹振荡器采用台积电40 nm CMOS工艺,基波工作频率为154.5 GHz,输出二次谐波为 309.0 GHz,输出功率可达-3.0 dBm,相位噪声为-79.5 dBc/Hz@1 MHz,功耗为28.6 mW,频率调谐范围为303.5~315.4 GHz。     

A W-band source module using MMIC's

A W-band source module providing 4-GHz tuning bandwidth (92.5-96.5 GHz) has been developed. This module consists of three MMIC chips: a 23.5 GHz HBT VCO, a 23.5-94 GHz HEMT frequency quadrupler and a W-band three-stage HEMT output amplifier, all fabricated in TRW production lines. It exhibits a measured output power of 3 dBm at 94-95 GHz and a 3-dB tuning bandwidth greater than 3 GHz, with a phase noise of -92 dBc/Hz at 1 MHz offset. This work demonstrates a new and efficient way to implement high performance W-band source. Its wide tuning bandwidth with good phase noise performance, as well as design simplicity, makes this approach attractive for many W-band system applications     

Varactor-tunable uniplanar ring resonators

Slotline and CPW ring resonators are introduced and integrated with varactor diodes to create electronically tunable uniplanar ring resonators. Varactors electronically tune the second resonant mode of the slotline ring over a 23% bandwidth from 3.03 to 3.83 GHz with a 4.5±1.5 dB variation in insertion loss. Similarly, a CPW ring resonator was tuned over a 22% bandwidth from 2.88 to 3.59 GHz. Both resonators offer the ground plane and center conductor on the same side of the substrate to allow easy series or shunt insertion of solid-state devices. DC biasing is naturally integrated in the slotline structure and straightforward in CPW. Monolithic implementation of these resonators would not require via holes to ground solid-state devices which should reduce processing complexity and increase production yields     

A compact CPW-based single-layer injection-locked active antennafor array applications

A compact single-layer coplanar waveguide (CPW)-fed active patch antenna oscillator at 9.81 GHz is presented based on a commercially available GaAs FET, which is centered behind the patch for tight packing. The positive feedback for the oscillation is accomplished through twin-slot aperture coupling to the patch. This results in a design having its longest dimension equal to 26.6 mm at 9.81 GHz. A low-power injection signal is applied to stabilize the oscillation through parasitic coupling at the CPW side of the circuit. This parasitic coupling is achieved by electromagnetic coupling of the locking signal to the gate of the FET. The measured effective isotropic radiated power is 19.6 dBm, whereas the worse-case front-to-back ratio is about 15 dB with the cross-polarized fields better than -20 dB at broadside. The measured phase noise of the unlocked and locked signals are -63.28 and -107.5 dBc/Hz, respectively, at a 100-kHz offset away from the carrier. This compact design is ideally suited as a unit cell in injection-locked phased-array architectures     

Wide tuning-range CMOS VCO based on a tunable active inductor

In this paper, a wide tuning-range CMOS voltage-controlled oscillator (VCO) with high output power using an active inductor circuit is presented. In this VCO design, the coarse frequency is achieved by tuning the integrated active inductor. The circuit has been simulated using a 0.18-µm CMOS fabrication process and presents output frequency range from 100 MHz to 2.5 GHz, resulting in a tuning range of 96%. The phase noise is –85 dBc/Hz at a 1 MHz frequency offset. The output power is from –3 dBm at 2.55 GHz to +14 dBm at 167 MHz. The active inductor power dissipation is 6.5 mW and the total power consumption is 16.27 mW when operating on a 1.8 V supply voltage. By comparing this active inductor architecture VCO with general VCO topology, the result shows that this topology, which employs the proposed active inductor, produces a better performance.