K-band and millimeter-wave MMICs for emerging commercial wirelessapplications

The recent K-band monolithic-microwave integrated-circuit (MMIC) technologies for the local multipoint distribution service systems and novel MMIC technologies for potential low-cost millimeter-wave MMICs are presented in this paper via a review of Fujitsu Quantum Devices Limited technology. The devices being demonstrated are a 23-26-GHz 2-W power amplifier module with a broad-band driver amplifier, a 19-33-GHz miniature low-noise amplifier, a frequency multiplier by four for K-band local oscillators, a flip-chip MMIC module for radar application, and three-dimensional MMIC image-rejection harmonic mixers. Through these devices, the recent trend of design and fabrication methodologies for the K-band and millimeter-wave devices will be described     

Highly Reliable High-Power 86-GHz Components and Transmitter--Receiver Modules

The reliability of semiconductor active devices is related to the junction temperature of diodes used. This paper describes the reliability design and performance of 86-GHz active components and transmitter-receiver modules for a guided millimeter-wave transmission system. The components are IMPATT oscillators, IMPATT amplifiers, varactor frequency multipliers, and Schottky-barrier diode upconverters. The maximum output powers of these active devices are calculated for a given mean time between failure (MTBF). Active components and transmitter-receiver modules for 86-GHz operation were manufactured based upon the design with considerations for reliability as well as RF performance.     

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     

Millimeter-wave generation and characterization of a GaAs FET byoptical mixing

Coherent mixing of optical radiation from a tunable continuous-wave dye laser and a stabilized He-Ne laser was used to generate millimeter-wave signals in GaAs FETs attached to printed-circuit millimeter-wave antennas. The generated signal was further down-converted to a 2-GHz IF by an antenna-coupled millimeter-wave local oscillator at 62 GHz. Detailed characterizations of power and S/N under different bias conditions have been performed. This technique is expected to allow signal generation and frequency-response evaluation of millimeter-wave devices at frequencies as high as 100 GHz     

Low phase noise millimeter-wave frequency sources using InP-basedHBT MMIC technology

A family of millimeter-wave sources based on InP heterojunction bipolar transistor (HBT) monolithic microwave/millimeter-wave integrated circuit (MMIC) technology has been developed. These sources include 40-GHz, 46-GHz, 62-GHz MMIC fundamental mode oscillators, and a 95-GHz frequency source module using a 23.8-GHz InP HBT MMIC dielectric resonator oscillator (DRO) in conjunction with a GaAs-based high electron mobility transistor (HEMT) MMIC frequency quadrupler and W-band output amplifiers. Good phase noise performance was achieved due to the low 1/f noise of the InP-based HBT devices. To our knowledge, this is the first demonstration of millimeter-wave sources using InP-based HBT MMIC's     

Dual-Harmonic Noncontacting Millimeter Waveguide Backshorts: Theory, Design, and Test

Noncontacting backshorts are necessary in many applications to avoid the wear characteristic of contacting shorts. To reduce losses, it is desirable to eliminate the passband at second harmonic frequencies inherent in conventional quarter-wavelength designs. To this effect, empirically and theoretically designed shorts have been fabricated. The theoretical design extends low-frequency Chebyshev filter theory techniques for use at millimeter-wave frequencies. Both designs have been tested using swept frequency reflectometer techniques. Tests have been carried out over a 40-GHz bandwidth at 100 GHz and a 30-GHz bandwidth at 200 GHz. The results are superior to those obtained with Lambda/ 4 backshorts tested in the same manner.     

A 44 GHz HEMT amplifier

A 44-GHz amplifier using 0.25-μm gate length and double-heterojunction structure HEMT devices is described. Higher gain and power performance have been obtained from the amplifier using this device at millimeter-wave frequencies. A spot gain of 9.4 dB and a 1-dB gain compression point of +7.5 dBm has been achieved at 43.5 GHz.     

Experimental Study of Series Connected TRAPATT Diodes (Short Papers)

The results of experiments using TRAPATT diodes connected in series at 0.5, 2, and 8 GHz are described. These experiments demonstrate that successful series operation of TRAPATT's at frequencies up to at least 2 GHz can be achieved in a configuration suitable for long pulsewidth or CW operation. An 8-GHz operation of series stacked TRAPATT'S yielded high power outputs at the same efficiency achieved with single devices but no well heat sunk configuration was found that yielded good efficiency.     

RF HBT oscillators with low-phase noise and high-power performance utilizing a (/spl lambda//4/spl plusmn//spl delta/) open-stubs resonator

This paper presents a new type of transmission-line resonator and its application to RF (microwave and millimeter-wave) heterojunction bipolar transistor (HBT) oscillators. The resonator is a parallel combination of two open stubs having length of /spl lambda//4/spl plusmn//spl delta/(/spl delta//spl Lt//spl lambda/), where /spl lambda/ is a wavelength at a resonant frequency. The most important feature of this resonator is that the coupling coefficient (/spl beta//sub C/) can be controlled by changing /spl delta/ while maintaining unloaded Q-factor (Q/sub u/) constant. Choosing a small value of /spl delta/ allows us to reduce /spl beta//sub C/ or equivalently to increase loaded Q-factor (Q/sub L/). Since coupling elements such as capacitors or electromagnetic gaps are not needed, /spl beta//sub C/ and Q/sub L/ can be precisely controlled based on mature lithography technology. This feature of the resonator proves useful in reducing phase noise and also in enhancing output power of microwave oscillators. The proposed resonator is applied to 18-GHz and 38-GHz HBT oscillators, leading to the phase noise of -96-dBc/Hz at 100-kHz offset with 10.3-dBm output power (18-GHz oscillator) and -104-dBc/Hz at 1-MHz offset with 11.9 dBm (38-GHz oscillator). These performances are comparable to or better than state-of-the-art values for GaAs- or InP-based planar-circuit fundamental-frequency oscillators at the same frequency bands.     

Submillimeter-wave InP Gunn devices

Recent advances in design and technology significantly improved the performance of low-noise InP Gunn devices in oscillators first at D-band (110-170 GHz) and then at W-band (75-110 GHz) frequencies. More importantly, they next resulted in orders of magnitude higher RF output power levels above D-band and operation in a second-harmonic mode up to at least 325 GHz. Examples of the state-of-the-art performance are continuous-wave RF power levels of more than 30 mW at 193 GHz, more than 3.5 mW at 300 GHz, and more than 2 mW at 315 GHz. The dc power requirements of these oscillators compare favorably with those of RF sources driving frequency multiplier chains to reach the same output RF power levels and frequencies. Two different types of doping profiles, a graded profile and one with a doping notch at the cathode, are prime candidates for operation at submillimeter-wave frequencies. Generation of significant RF power levels from InP Gunn devices with these optimized doping profiles is predicted up to at least 500 GHz and the performance predictions for the two different types of doping profiles are compared.     

Indirect Subharmonic Optical Injection Locking of a Millimeter-Wave IMPATT Oscillator

Large aperture phased-array antennas operating at millimeter-wave frequencies are designed for space-based communications and imaging. Array elements are composed of active transmit-receive (T/R) modules that are phase and frequency synchronized to a reference signal at the central processing unit by a fiber-optic (FO) distribution network. The implementation of FO links, synchronizing the millimeter-wave Iocal oscillators (LO's), imposes a great challenge. This paper presents results of indirect optical injection locking of a free-running 38-GHz (Ka-band) IMPATT oscillator over the Iocking range of 2-132 MHz, depending on the injected power level (amplifier gain). In the experiment, the nonlinearity of both the laser diode and the IMPATT oscillator is exploited to achieve 12th subharmonic injection locking. The overall system FM noise degradation of the reference signal is 16 dB at 500-Hz offset. The FM noise degradation is dominated by the theoretical limit of 20 log N, where N is the frequency multiplication factor used in subharmonic injection locking. Methods by which optical injection locking may be extended into 60 and 90 GHz are demonstrated.     

A 23-dBm 60-GHz Distributed Active Transformer in a Silicon Process Technology

In this paper, a distributed active transformer for the operation in the millimeter-wave frequency range is presented. The transformer utilizes stacked coupled wires as opposed to slab inductors to achieve a high coupling factor of k_f=0.8 at 60 GHz. Scalable and compact equivalent-circuit models are used for the transformer design without the need for full-wave electromagnetic simulations. To demonstrate the feasibility of the millimeter-wave transformer, a 200-mW (23 dBm) 60-GHz power amplifier has been implemented in a standard 130-nm SiGe process technology, which, to date, is the highest reported output power in an SiGe process technology at millimeter-wave frequencies. The size of the output transformer is only 160times160 mum² and demonstrates the feasibility of efficient power combining and impedance transformation at millimeter-wave frequencies. The two-stage amplifier has 13 dB of compressed gain and achieves a power-added efficiency of 6.4% while combining the power of eight cascode amplifiers into a differential 100-Omega load. The amplifier supply voltage is 4 V with a quiescent current consumption of 300 mA     

Double-drift-region ion-implanted millimeter-wave IMPATT diodes

A detailed experimental comparison between double-drift-region (DDR) and single-drift-region (SDR) millimeter-wave avalanche diodes is presented. For 50-GHz CW operation, DDR diodes have given a maximum of 1-W output power compared to 0.53 W for the SDR diodes, while maximum efficiencies of 14.2 percent for the DDR and 10.3 percent for the SDR diodes have been obtained. These results are in agreement with the theory of Scharfetter et al. [1] for DDR IMPATT diodes. Both the DDR and SDR diode measurements were made on room temperature, metal heat sinks. The DDR diodes were shown to operate at significantly lower junction temperatures for the same value of output power, indicating a potential reliability advantage. Ion implantation was used to make the p drift region of the p⁺p-n-n⁺50-GHz DDR devices. Otherwise the fabrication (which includes diffusion and epitaxial technologies) and the microwave measurement methods were identical for both types of diodes. Capacitance measurements were compared with calculations to determine the desired doping concentrations for frequencies from 43 to 110 GHz. Experimental results for the higher frequency millimeter-wave region have been obtained on DDR structures with both p and n drift regions implanted. At 92 GHz an output power of 0.18 W and an efficiency of 7.4 percent have been obtained.     

An Empirical Design Technique for Microwave Oscillators (Short Papers)

A large-signal design technique for series-type microwave oscillators using three-terminal active devices is described. Using this technique, the characteristics of the embedding circuits required for maximum output power are measured directly under actual oscillation conditions. A two-signal technique is used in the measurement to establish the required oscillation conditions and to prevent oscillation at unwanted frequencies. The design technique has been verified by the construction of a 2.7-GHz bipolar transistor oscillator.     

Millimeter-wave InP lateral transferred-electron oscillators

A lateral InP transferred-electron device (TED) designed with a high-resistivity notch adjacent to the cathode contact is presented, and its application to millimeter-wave monolithic integrated circuits is demonstrated. At 29.9 GHz, a CW power output of 29.1 mW with a conversion efficiency of 6.7% has been obtained from cavity-tuned discrete devices. This result represents the highest power output and efficiency of a lateral TED in this frequency range. The lateral devices also had a CW power output of 0.4 mW at 98.5 GHz and 0.9 mW at 75.2 GHz. A 79.9-GHz monolithic oscillator incorporating the lateral TED is reported. Experimental and theoretical results which further the understanding of the lateral device operation are presented     

A 31-GHz monolithic GaAs mixer/preamplifier circuit for receiver applications

The portion of a monolithic receiver containing integrated Schottky mixer diodes and MESFET'S with microstrip circuitry has been developed and tested at 31 GHz. This work is part of a program to establish the feasibility of monolithic receivers and transmitters at microwave and millimeter-wave frequencies. Receiver designs using high-cutoff frequency diodes in a mixer configuration followed by a MESFET amplifier are capable of operating from microwave through millimeter-wave frequencies. However, the fabrication of monolithic receiver designs requires the integration on the same wafer of devices with different material requirements. We have developed a compatible integration scheme which is fundamental to the fabrication of monolithic receivers at millimeter-wave frequencies. Fabrication and design considerations for the 31-GHz balanced mixer and IF preamplifier are described. Completed monolithic units typically exhibit a conversion gain of 4 dB from the signal frequency of 31 GHz to the IF frequency of 2 GHz. The associated noise figure is typically 11.5 dB.     

Wideband Circulators for Use at Frequencies Above 100 GHz to Beyond 350 GHz

High-performance circulators operating at frequencies in the range from 100 to 350 GHz have been developed for application in major measurement systems. These circulators have open quasi-optical structures. The magnetized plates in these devices are of nonmetallic magnetic materials which have both well-developed millimeter-wave gyrotropic properties and the magnetostatic properties of an excellent permanent magnet material. Very few commercially available magnetic materials have been found that meet both the magnetostatic and the magnetooptical selection criteria. Those few have, however, made possible the design, manufacture, and successful operation of high-performance circulators/isolators at these high operating frequencies. Several circulators/isolators of this type have been installed in major measurement systems.     

Microstrip Varactor-Tuned Millimeter-Wave IMPATT Diode Oscillators

Varactor-tuned millimeter-wave IMPATT diode oscillators in microstrip form using chip-mounted diodes are described. A nearly level output power of 28 /spl plusmn/ 8 mW was achieved over a 6-GHz tuning range. Tunable bandwidths as high as 8 GHz with 6-26 mW of power were obtained from a single source. P-type epitaxial silicon IMPATT diodes were used for both the active device and the tuning varactor functions.     

Millimeter-wave voltage-controlled oscillators in 0.13-/spl mu/m CMOS technology

This paper describes the design of CMOS millimeter-wave voltage controlled oscillators. Varactor, transistor, and inductor designs are optimized to reduce the parasitic capacitances. An investigation of tradeoff between quality factor and tuning range for MOS varactors at 24 GHz has shown that the polysilicon gate lengths between 0.18 and 0.24 /spl mu/m result both good quality factor (>12) and C/sub max//C/sub min/ ratio (/spl sim/3) in the 0.13-/spl mu/m CMOS process used for the study. The components were utilized to realize a VCO operating around 60 GHz with a tuning range of 5.8 GHz. A 99-GHz VCO with a tuning range of 2.5 GHz, phase noise of -102.7 dBc/Hz at 10-MHz offset and power consumption of 7-15mW from a 1.5-V supply and a 105-GHz VCO are also demonstrated. This is the CMOS circuit with the highest fundamental operating frequency. The lumped element approach can be used even for VCOs operating near 100-GHz and it results a smaller circuit area.     

Efficient generation of guided millimeter-wave power by photomixing

A 70-GHz bandwidth commercial photodiode has been coupled to W-band waveguide and used as a photomixing source from 75 to 170 GHz. Maximum power conversion efficiency of 1.8% was obtained at 75 GHz, where an optical input of +10 dBm yielded a nonsaturated millimeter-wave (mm-wave) power of -7.5 dBm. Optimizing the photomixer backshort tuning at individual frequencies showed that the mm-wave power decreased with frequency to a level of -30 dBm at 170 GHz. Fixed tuning allowed the generation of power across the full waveguide band from 75 to 110 GHz, with a variation within 5 dB across the majority of the band