High-dynamic-range airborne tracking and fire control radarsubsystem

Two high-dynamic-range receiver subsystems for use in airborne radar fire control and tracking applications are described. The X -band dual-channel monopulse tracking receiver operates at 9.36±0.290 GHz with a 6-dB noise figure and a linear instantaneous dynamic range of 42 dB. A total of 80 dB of RF and IF gain control is programmable with less than ±15° phase and ±1 dB amplitude tracking errors. The Doppler radar receiver operates at 9.3±0.15 GHz and has a 4.6-dB noise figure with ⩾80 dB of instantaneous dynamic range. An 18-dB sensitivity time control (STC) circuit and a 60-dB dump attenuator allow close-in target reception     

A 30-GHz monolithic receiver

Several monolithic integrated circuits have been developed to make a 30-GHz receiver. The receiver components include a low-noise amplifier, an IF amplifier, a mixer, and a phase shifter. The LNA has a 7-dB noise figure with over 17 dB of associated gain. The IF amplifier has a 13-dB gain with a 30-dB control range. The mixer has a conversion loss of 10.5 dB. The phase shifter has a 180° phase shift control and a minimum insertion loss of 1.6 dB.     

A low-voltage and variable-gain distributed amplifier for 3.1-10.6 GHz UWB systems

A low-voltage and variable-gain distributed amplifier is presented in this letter. This microwave monolithic integrated circuit amplifier achieves 12-dB gain with a 3-dB frequency band of 1.6-12.1GHz and 6.5-dB noise figure under the bias condition of 0.8-V supply voltage and 6.4-mW total dc power consumption. The gain-control range is from -18dB to +20dB. Resistive metal-oxide-semiconductor field-effect transistors are used as termination resistors to compensate the mismatch due to different bias conditions. From 3.1 to 10.6GHz, the maximum gain ripple of this amplifier is only /spl plusmn/1dB for the gain level between -4 and 20dB.     

Design and Performance of Microwave Amplifiers with GaAs Schottky-Gate Field-Effect Transistors

The design and performance of an X-band amplifier with GaAs Schottky-gate field-effect transistors are described. The amplifier achieves 20 /spl plusmn/ 1.3-dB gain with a 5.5-dB typical noise figure (6.9 dB maximum) over the frequency range of 8.0-12.0 GHz. The VSWR at the input and output ports does not exceed 2.5:1. The minimum output power for 1-dB gain compression is +13 dBm, and the intercept point for third-order intermodulation products is +26 dBm. The design of practical wide-band coupling networks is discussed. These networks minimize the overall amplifier noise figure and maintain a constant gain in the band.     

GaAs Monolithic MIC's for Direct Broadcast Satellite Receivers

A 12-GHz low-noise amplifier (LNA), a 1-GHz IF amplifier (IFA), and an 11-GHz dielectric resonator oscillator (DRO) have been developed for DBS home receiver applications by using GaAs monolithic microwave integrated circuit (MMIC) technology. Each MMIC chip contains FET's as active elements and self-biasing source resistors and bypass capacitors for a single power supply operation. It also contairns dc-block and RF-bypass capacitors. The three-stage LNA exhibits a 3.4-dB noise figure and a 19.5-dB gain over 11.7-12.2 GHz. The negative-feedback-type three-stage IFA shows a 3.9-dB noise figure and a 23-dB gain over 0.5-1.5 GHz. The DRO gives 10.mW output power at 10.67 GHz, with a frequency stability of 1.5 MHz over a temperature range from -40-80°C. A direct broadcast satellite (DBS) receiver incorporating these MMIC's exhibits an overafl noise figure of /spl les/ 4.0 dB for frequencies from 11.7-12.2 GHz.     

A low-power low-noise accurate linear-in-dB variable-gain amplifierwith 500-MHz bandwidth

A linear-in-dB variable-gain amplifier (VGA) using a pre-distortion circuit to generate the gain-control signal is fabricated in a BiCMOS process with f_T=20 GHz. The VGA comprises two cascaded stages of signal-summing VGA and has a variable-gain range of over 70 dB. It can operate at up to 500 MHz and dissipates 36 mW from a 3-V supply. A noise figure of below 5 dB and IIP3 of over -38 dBm at 43-dB gain were obtained. The VGA achieved a gain error of less than 2 dB over 70-dB gain range, and it occupies approximately 1 mm². The VGA is applicable to future code division multiple access (CDMA) receivers     

Low-power-consumption and high-gain CMOS distributed amplifiers using cascade of inductively coupled common-source gain cells for UWB systems

A distributed amplifier with new cascade inductively coupled common-source gain-cell configuration is presented. Compared with other existing gain-cell configurations, the proposed cascade common-source gain cell can provide much higher transconductance and, hence, gain. The new distributed amplifier using the proposed gain-cell configuration, fabricated via a TSMC 0.18-/spl mu/m CMOS process, achieves an average power gain of around 10 dB, input match of less than -20 dB, and noise figure of 3.3-6.1 dB with a power consumption of only 19.6 mW over the entire ultra-wideband (UWB) band of 3.1-10.6 GHz. This is the lowest power consumption ever reported for fabricated CMOS distributed amplifiers operating over the whole UWB band. In the high-gain operating mode that consumes 100 mW, the new CMOS distributed amplifier provides an unprecedented power gain of 16 dB with 3.2-6-dB noise figure over the UWB range.     

Low-power W-band CPWG InAs/AlSb HEMT low-noise amplifier

We present the development of a low-power W-band low-noise amplifier (LNA) designed in a 200-nm InAs/AlSb high electron mobility transistor (HEMT) technology fabricated on a 50-/spl mu/m GaAs substrate. A single-stage coplanar waveguide with ground (CPWG) LNA is described. The LNA exhibits a noise figure of 2.5 dB and an associated gain of 5.6 dB at 90 GHz while consuming 2.0 mW of total dc power. This is, to the best of our knowledge, the lowest reported noise figure for an InAs/AlSb HEMT LNA at 90 GHz. Biased for maximum gain, the single-stage amplifier presents 6.7-dB gain and an output 1-dB gain compression point (P1dB) of -6.7dBm at 90 GHz. The amplifier provides broad-band gain, greater than 5dB over the entire W-band.     

5-60-GHz high-gain distributed amplifier utilizing InP cascodeHEMTs

A high-gain InP MMIC cascode distributed amplifier was developed which has 12 dB of gain from 5 to 60 GHz with over 20-dB gain control capability and a noise figure of 2.5-4 dB in the Ka band. Lattice-matched InAlAs/InGaAs cascode HEMTs on InP substrate with 0.25-μm gate length were the active devices. Microstrip was the transmission medium for this MMIC with an overall chip dimension of 2.3 mm×0.9 mm. The gain/noise figure advantages of the InP HEMT over the AlGaAs HEMT and the superior gain performance of the cascode HEMT over the common-source HEMT are demonstrated     

Performance of GaAs MESFET's at Low Temperatures (Short Papers)

The noise- and s-parameters of a GaAs MESFET with 1-mu m gate Iength are characterized versus temperature. At room temperature, the noise figure measured at 12 GHz is 3.5 dB. At 90 K, the noise figure decreases to 0.8 dB (T/sub e/ = 60 K). The associated gain is 8 dB. The design of a cooled amplifier for the 11.7-12.2-GHz communication band is discussed. At 60 K, the three-stage amplifier exhibits 1.6-dB noise figure (T/sub e/ = 130 K) and 31-dB gain.     

Low-noise intelligent cladding-pumped L-band EDFA

We present results on a low-cost cladding-pumped L-band amplifier based on side pumping (GTWave) fiber technology and pumped by a single 980-nm multimode diode. We show that simultaneous noise reduction and transient suppression can be achieved by using gain clamping by a seed signal (/spl lambda/=1564 nm). In the gain-clamping regime, the amplifier exhibits 30-dB gain over 1570-1605-nm spectral band with noise figure below 7 dB. The noise figure can be further reduced to below 5 dB by utilizing a low power single-mode pump at 980 nm. The erbium-doped fiber amplifier is relatively insensitive to input signal variations with power excursions below 0.15 dB for a 10-dB channel add-drop.     

W-band low-noise InAlAs/InGaAs lattice-matched HEMTs

Very low-noise 0.15-μm gate-length W-band In_0.52 Al_0.48As/In_0.53Ga_0.47As/In _0.52Al_0.48As/InP lattice-matched HEMTs are discussed. A maximum extrinsic transconductance of 1300 mS/mm has been measured for the device. At 18 GHz, a noise figure of 0.3 dB with an associated gain of 17.2 dB was measured. The device also exhibited a minimum noise figure of 1.4 dB with 6.6-dB associated gain at 93 GHz. A maximum available gain of 12.6 dB at 95 GHz, corresponding to a maximum frequency of oscillation, f_max, of 405 GHz (-6-dB/octave extrapolation) in the device was measured. These are the best device results yet reported. These results clearly demonstrate the potential of the InP-based HEMTs for low-noise applications, at least up to 100 GHz     

Ultrawide-band La-codoped Bi/sub 2/O/sub 3/-based EDFA for L-band DWDM systems

The demonstration of a 253-cm-long lanthanum-codoped Bi/sub 2/O/sub 3/-based erbium-doped fiber which provides gain of greater than 20 dB and noise figure less than 6.7 dB to 142 dense wavelength-division-multiplexing channels simultaneously over an extended wavelength range of 58 nm from 1554 to 1612 nm is reported. The 3-dB (gain of 17-20 dB) bandwidth of the erbium-doped fiber amplifier is 54 nm when it is pumped with 350 mW of 1480-nm light. The power conversion efficiency of the fiber is about 54%.     

Performance of Dual-Gate GaAs MESFET's as Gain-Controlled Low-Noise Amplifiers and High-Speed Modulators

This paper describes the microwave performance of GaAs FET's with two 1-mu m Schottky-barrier gates (dual-gate MESFET). At 10 GHz the MESFET, with an inductive second-gate termination, exhibits an 18-dB gain with --26-dB reverse isolation. Variation of the second-gate potential yields a 44-dB gain-modulation range. The minimum noise figure is 4.0 dB with 12-dB associated gain at 10 GHz. Pulse modulation of an RF carrier with a 65-ps fall ad a 100-ps rise time is demonstrated. The dual-gate MESFET with high gain and low noise figure is especially suited for receiver amplifiers with automatic gain control (AGC) as an option. The MESFET is equally attractive for subnanosecond pulsed-amplitude modulation (PAM), phase-shift-keyed (PSK), and frequency-shift-keyed (FSK) carrier modulation.     

A study of millimeter-wave GaAs IMPATT oscillator and amplifier noise

Noise characterization of a set of epitaxially grown p-n-junction GaAs IMPATTS that operate efficiently from 26-35 GHz is reported. In oscillator operation, the diodes exhibit an excess noise near the carrier, which follows a 1/fdependence. Far from the carrier an AM DSB SNR of 134 dB in a 100-Hz window and an FM noise measure of 36 dB are observed. As a reflection amplifier, a gain of 22 dB with a 250-MHz bandwidth and a noise figure of 25.5 dB is achieved. Under higher gain conditions (28-dB gain) a 24-dB figure is obtained.     

110-120-GHz monolithic low-noise amplifiers

The authors discuss the development of 110-120-GHz monolithic low-noise amplifiers (LNAs) using 0.1-mm pseudomorphic AlGaAs/InGaAs/GaAs low-noise HEMT technology. Two 2-stage LNAs have been designed, fabricated, and tested. The first amplifier demonstrates a gain of 12 dB at 112 to 115 GHz with a noise figure of 6.3 dB when biased for high gain, and a noise figure of 5.5 dB is achieved with an associated gain of 10 dB at 113 GHz when biased for low-noise figure. The other amplifier has a measured small-signal gain of 19.6 dB at 110 GHz with a noise figure of 3.9 dB. A noise figure of 3.4 dB with 15.6-dB associated gain was obtained at 113 GHz. The authors state that the small-signal gain and noise figure performance for the second LNA are the best results ever achieved for a two-stage HEMT amplifier at this frequency band     

Ultra-low-noise indium-phosphide MMIC amplifiers for 85-115 GHz

This paper describes a high-performance indium-phosphide monolithic microwave integrated circuit (MMIC) amplifier, which has been developed for cooled application in ultra-low-noise imaging-array receivers. At 300 K, the four-stage amplifier exhibits more than 15-dB gain and better than 10-dB input and output return loss from 80 to 110 GHz. The room-temperature noise figure is typically 3.2 dB, measured between 90-98 GHz. When cooled to 15 K, the gain increases to more than 18 dB and the noise figure decreases to 0.5 dB. Only one design pass was required to obtain very good agreement between the predicted and measured characteristics of the circuit. The overall amplifier performance is comparable to the best ever reported for MMIC amplifiers in this frequency band     

Super low-noise GaAs MESFET's with a deep-recess structure

Super low-noise GaAs MESFET's for replacement of parametric amplifiers have been successfully developed by adopting a deep-recess structure. The structure of a 0.5-µm gate in a deeply recessed region with a cylindrical edge shape has enabled reduction of the source resistance to a half of that of conventional flat-type MESFET's. The noise figure was improved by more than 0.5 dB by this reduction of the source resistance, and less than 2.0-dB noise figure has been reproducibly obtained at 12 GHz. The best noise figures were 0.7 dB (14.9-dB gain) at 4 GHz and 1.68 dB (10.7-dB gain) at 12 GHz. The developed MESFET's were applied to two-stage amplifiers of 11.7-12.2-GHz band, and the noise figure obtained was 2.16 dB (T_{e}: 185K) at room temperature and 1.94 dB (T_{e}: 163K) at 0°C. This performance is good enough to replace some of parametic amplifiers.     

A 60-dB 246-MHz CMOS variable gain amplifier for subsampling GSM receivers

A variable gain amplifier (VGA) is designed for a GSM subsampling receiver. The VGA is implemented in a 0.35-/spl mu/m CMOS process and approximately occupies 0.64 mm/sup 2/. It operates at an IF frequency of 246 MHz. The VGA provides a 60-dB digitally controlled gain range in 2-dB steps. The overall gain accuracy is less than 0.3 dB. The current is 9 mA at 3 V supply. The noise figure at maximum gain is 8.7 dB. The IIP3 is -4 dBm at minimum gain, while the OIP3 is -1 dBm at maximum gain. The group delay is 1.5 ns across 5-MHz bandwidth.     

Super-low-noise performance of direct-ion-implanted 0.25-μm-gateGaAs MESFET's

The authors report on advanced ion implantation GaAs MESFET technology using a 0.25-μm `T' gate for super-low-noise microwave and millimeter-wave IC applications. The 0.25×200-μm-gate GaAs MESFETs achieved 0.56-dB noise figure with 13.1-dB associated gain at 50% I_DSS and 0.6 dB noise figure with 16.5-dB associated gain at 100% I_DSS at a measured frequency of 10 GHz. The measured noise figure is comparable to the best noise performance of AlGaAs/GaAs HEMTs and AlGaAs/InGaAs/GaAs pseudomorphic HEMTs