Low-Noise Cooled GASFET Amplifiers

Measurements of the noise characteristics of a variety of gallium-arsenide field-effect transistors at a frequency of 5 GHz and temperatures of 300 K to 20 K are presented. For one transistor type detailed measurements of dc parameters, small-signal parameters, and all noise parameters (T/sub min/, R/sub opt/, X/sub opt/ g/sub n/) are made over this temperature range. The results are compared with the theory of Pucel, Haus and Statz modified to include the temperature variation. Several low-noise ampifiers are described including one with a noise temperature of 20 K over a 500-MHz bandwidth. A theoretical analysis of the thermal conduction at cryogenic temperatures in a typical packaged transistor is included.     

GaAsFET Mount Structure Design for 30-GHz-Band Low-Noise Amplifiers

This paper describes a GaAsFET mount design method for 30-GHz-band low-noise reflection-type amplifiers with the metal wall as a feedback circuit. Two examples of 30-GHz-band low-noise amplifiers are described; one with wide-band response and the other with high-gain response. The wide-band amplifier has 13-dB gain and 8.5-dB noise figure in the frequency range from 27.5 GHz to 29.1 GHz. The high gain amplifier has 15-dB gain and 9-dB noise figure in the frequency range from 27.7 GHz to 28.7 GHz. These results demonstrate the utility of this design approach.     

Temperature-Stabilized 1.7-GHz Broad-Band Lumped-Element Circulator

A new construction technique for broad-banding and temperature stabilization of a lumped-element circulator is presented to obtain a compact circulator for practical usage. By using a new integrated wide-banding network consisting of three series resonant circuits on the back of the junction substrate, 1.7-GHz double-tuned and triple-tuned broad-band circulators have been successfully developed. Fundamental junction parameters, such as an in-phase eigeninductance, parasitic capacitance, and nonreciprocal filling factor, have been investigated experimentally. A design theory for temperature compensation of a lumped-element circulator is also presented, and temperature compensation with bias magnetic field of postitive temperature coefficient has been applied to the 1.7-GHz broad-band circulators. As a result, 20-dB isolation bandwidths of more than 600 MHz (double-tuned type) and 950 MHz (triple-tuned type) have been obtained throughout the temperature range of -10 ~ +60/spl deg/C.     

Design parameters of a high-efficiency 1.7-GHz gyropeniotronamplifier

The feasibility of the gyropeniotron amplifier as a high-efficiency, high-power RF source to act as driver for accelerator in the 0.8-1.7-GHz frequency range is discussed. The klystrode is difficult to operate in this frequency range. Design parameters are given for a 1.7-GHz gyropeniotron operating with an axis-encircling beam (100 keV, 10 A) in a magnetron-type slotted waveguide. The external magnetic field required is 326 G. The calculated efficiency for second cyclotron harmonic operation is 78% with a cold beam and 66% with a beam having 2% axial velocity spread and 5% guiding center spread. The depressed collector technique can easily be applied to enhance the efficiency since the spent beam in a gyropeniotron has little velocity spread     

Adaptive nulling loop control for 1.7-GHz feedforward linearizationsystems

An adaptive analog control system is introduced for the nulling loop (first loop) of a 1.7-GHz feedforward linearization system. The sensitivity to temperature and frequency variations is experimentally shown for a conventional feedforward system, leading to the need for an adaptive control system. Two error signals based on detected power levels are introduced and used to control the nulling loop vector modulator to ensure cancellation of the main signal. Finally, the experimental performance of this system is presented     

Bulk optical isolator tunable from 1.2 ?m to 1.7 ?m

A uniquely designed, mechanically tunable, bulk optical isolator for the 1.2 to 1.7 ?m wavelength range is described. The isolator can be tuned for isolation better than 32 dB over the operating wavelength range with a forward loss ranging from -3.6 dB at 1.2 ?m to -0.8 dB at 1.6 ?m.     

Design and Performance of I-Band (8-10-GHz) TRAPATT Diodes and Amplifiers

The design and fabrication of I-band silicon TRAPATT diodes are described, and the results of both oscillator and amplifier measurements are presented. The paper includes details of the design and characterization of a cascaded three-stage TRAPATT amplifier.     

A 22--24-GHz Cryogenically Cooled GaAs FET Amplifier

This paper describes the design and performance of a cryogenically cooled low-noise FET amplifier operating in the 22-24-GHz range. The amplifier employs five cascaded single-ended gain stages and an integral bandpass filter. Noise temperatures in the 200 K range with an associated gain of 28 dB are typical for the nine cooled units built to date.     

Demonstration of 184 and 255-GHz Amplifiers Using InP HBT Technology

In this letter, 184 and 255 GHz single-stage heterojunction bipolar transistor (HBT) amplifiers are reported. Each amplifier uses a single-emitter 0.4 mum 15 mum InP HBT device with maximum frequency of oscillation (f_max) greater than 500 GHz and of 200 GHz. The 183 GHz single-stage amplifier has demonstrated gain of 4.3 plusmn 0.4 dB for all sites on the wafer. The 255 GHz amplifier has measured gain of 3.5d B and demonstrates the highest frequency measured HBT amplifier gain reported to date. Both amplifiers show excellent agreement with original simulation.     

A 3.5-mW, 2.5-GHz diversity receiver and a 1.2-mW, 3.6-GHz VCO insilicon on anything

In this paper, first results of radio-frequency (RF) circuits processed in a novel silicon bipolar technology called silicon on anything (SOA) are presented. This technology was developed with the application of low-power, high-frequency circuits in mind. Three test ICs are discussed: a fully integrated 3.6-GHz voltage-controlled oscillator, a fully integrated 2.5-GHz diversity receiver front end, and an intermediate-frequency IC containing channel selectivity and demodulation circuits. Measurement results show that using this technology, significant power savings are possible for RF circuits     

Design of a 1.7-GHz low-power delay-fault-testable 32-b ALU in 180-nm CMOS technology

In this paper, we present the design of a 32-b arithmetic and log unit (ALU) that allows low-power operation while supporting a design-for-test (DFT) scheme for delay-fault testability. The low-power techniques allow for 18% reduction in ALU total energy for 180-nm bulk CMOS technology with minimal performance degradation. In addition, there is a 22% reduction in standby mode leakage power and 23% lower peak current demand. In the test mode, we employ a built-in DFT scheme that can detect delay faults while reducing the test-mode automatic test equipment clock frequency.     

A 1.2-V 37–38.5-GHz Eight-Phase Clock Generator in 0.13- μm CMOS Technology

A 37-38.5-GHz clock generator is presented in this paper. An eight-phase LC voltage-controlled oscillator (VCO) is presented to generate the multiphase outputs. The high-pass characteristic CL ladder topology sustains the high-frequency signals. The split-load divider is presented to extend the input frequency range. The proposed PD improves the static phase error and enhances the gain. To verify the function of each block and modify the operation frequency, two additional testing components-an eight-phase VCO and a split-load frequency divider-are fabricated using 0.13-mum CMOS technology. The measured quadrature-phase outputs of VCO and input sensitivity of the divider are presented. This clock generator has been fabricated with 0.13-mum CMOS technology. The measured rms clock jitter is 0.24 ps at 38 GHz while consuming 51.6 mW without buffers from a 1.2-V supply. The measured phase noise is -97.55 dBc/Hz at 1-MHz offset frequency     

A 60- to 96-GHz high-temperature pressure window

Construction details of a mica millimeter-wave pressure window are given. Insertion loss under 0.4 dB from 60 to 90 GHz was achieved.     

Lack of microbial genetic response to 2.45-GHz CW and 8.5- to 9.6-GHz pulsed microwaves.

Strain D4 of the yeast Saccharomyces cerevisiae, and strains TA-1535, TA-100 and TA-98 of the bacterium Salmonella typhimurium, were exposed to 2.45-GHz continuous wave or 8.5- to 9.6-GHz pulsed electromagnetic radiation (EMR) at various power densities from 1 to 45 mW/cm2. The temperature during radiation was maintained at 30 degrees C for yeast cultures and at 37 degrees C for bacterial cultures. The studies revealed no increase in mutations or of mitotic gene conversions when cells were radiated for two hours or less. Decreased viability of cells was noted in all cultures tested after radiation at power densities of 30 mW/cm2 or more; however, no reliable changes in genetic events occurred.     

A 104- to 112.8-GHz CMOS Injection-Locked Frequency Divider

A high-frequency CMOS injection-locked frequency divider (ILFD) is presented by using the distributed LC, series inductor peaking, and multiple-injection techniques. The theoretical analysis for the aforementioned techniques will be given. This ILFD has been fabricated in a 65-nm CMOS process. The core area is 0.4 mm times 0.36 mm without pads. The measured locking range is from 104 to 112.8 GHz, and its power consumption is 7.2 mW from a supply of 1.2 V.     

A 26- to 40-GHz fast-acting plasma waveguide switch

A fast-acting broad-band plasma waveguide switch has been developed which provides greater than 60-dB isolation and less than 0.25-dB cold loss over the 26-to 40-GHz frequency range. Switching times are under 200 ns, and the actuating trigger signal is a 150-volt 0.5-µs pulse from a high-impedance source. Geometrical enhancement of plasma density by employing metallic convergence cones is used. This technique provides a moderately ionized plasma from a beam whose strength would normally provide only a weakly ionized plasma in the absence of the convergence cone. A computer program of the transmission equation using a plasma slab model yielded the average plasma density and slab thickness in the waveguide; electric probes were used to detect electron temperatures along the cone axis.     

A 125-260-GHz Gyrotron

The second gyrotron constructed at the University of Sydney has produced continuous microwave output at more than 60 frequencies in the range 125-260 GHz at power levels approaching 10 W. A gyrotron Iike this, with broad frequency coverage and moderate power output, has a wide range of possible applications, from spectroscopy to scattering from waves and fluctuations in plasmas. In this paper, the results of detailed measurements of frequency, magnetic field, frequency pulling, and starting current are compared with theory. Agreement is excellent. We find that mode conversion at the output end of the cavity determines the level of output power.     

A 0.8-V 4.9-mW 1.2-GHz CMOS Fractional-N Frequency Synthesizer for UHF RFID Readers

A fully integrated CMOS frequency synthesizer for UHF RFID reader is implemented in a 0.18-$mu$m CMOS technology. Due to the large self-interference and the backscatter scheme of the passive tags, reader synthesizer's phase noise requirement is stringent to minimize the sensitivity degradation of the reader RX. The modified transformer feedback voltage-controlled oscillator (VCO) exhibits enhanced tank impedance and even harmonic noise filtering to achieve low phase noise. A third-order 2-bit single-loop $Sigma Delta$ modulator is optimized for the proposed synthesizer in terms of phase noise and power. The synthesizer provides a frequency resolution of 25-kHz with a tuning range from 1.03 GHz to 1.4 GHz . Phase noise of ${-}$70 dBc/Hz inband, ${-}$104 dBc/Hz at 200-kHz offset and ${-}$ 121 dBc/Hz at 1-MHz offset with a reference spur of ${-}$84 dBc are measured at a center frequency of 1.17 GHz and a loop bandwidth of 35 kHz. Power dissipation is 4.92 mW from a 0.8 V supply.      

Backward-wave oscillators for the 50- to 300-GHz frequency range

A series of backward-wave oscillators for the 50-to 300-GHz frequency range have been built for use as broad-band signal sources which are capable of continuous and rapid voltage tuning. It is the purpose of this correspondence to summarize the design and performance of these oscillators in order to provide a broad characterization of this class of device.