Single-sideband Noise Figure Research Articles

A class AB monolithic mixer for 900-MHz applications

A class AB downconversion mixer for 900-MHz applications is presented. The circuit is implemented in a 25-GHz f/sub T/ bipolar process and consumes 10.2 mA total current from a 3-V supply. The design has a power gain of 7.5 dB and operates with supply voltages from 2.7 to 5 V. A single-sideband noise figure of 7.5 dB is achieved by design simplicity, use of bond-wire degeneration in the common-emitter driver stage, and optimization of the device sizes and bias currents. An input 1-dB compression point of -1.5 dBm is achieved by exploiting the class AB behavior of the common-emitter driver stage.

On the measurement of SSB noise figure using sideband cancellation

A new method for determining the single-sideband noise figure of a device from double-sideband measurements is proposed which eliminates the need for tunable filters and hence greatly reduces the complexity and cost of performing accurate noise figure measurements. This paper compares results obtained to those obtained using a traditional single-sideband measurement system with a tuneable filter and provides a full error analysis of the new technique. The method also offers considerable possibilities for future use at higher (microwave) frequencies where YIG filters and image reject mixers are not readily available.

A novel active antenna with self-mixing and wideband varactor-tuning capabilities for communication and vehicle identification applications

A cavity-backed, Gunn-diode-driven, self-mixing active inverted stripline circular patch antenna has been developed. The antenna provides good radiation performance with cross-polarization levels 18 dB below copolarization at boresight. The self-mixing performance shows that the circuit has a 2 dB conversion gain for IFs up to 450 MHz and a single-sideband noise figure of 12 dB at 200 MHz. The self-mixing antenna is also capable to mix signals with its second-harmonic, providing a conversion loss of 3.7 dB. Also, a varactor diode has been incorporated with a inverted stripline circular patch active antenna to allow for electronic tuning. A 13% tuning bandwidth with a power variation of 11.0 dB was achieved. A simple equivalent circuit has been used to model the active antenna, and the calculated results agree well with the experimental results. The circuit should have many commercial applications in wireless communications, radar, and sensors, but is particularly suitable for use as a transceiver for short communications links or as a microwave identification transceiver.

A 1.9 GHz low-voltage silicon bipolar receiver front-end for wireless personal communications systems

A 1.9 GHz wireless receiver front-end (low-noise preamplifier and mixer) is described that incorporates monolithic microstrip transformers for significant improvements in performance compared to silicon broadband designs. Reactive feedback and coupling elements are used in place of resistors to lower the front-end noise figure through the reduction of resistor thermal noise, and this also allows both circuits to operate at supply voltages below 2 V. These circuits have been fabricated in a production 0.8 /spl mu/m BiCMOS process that has a peak npn transistor transit frequency (f/sub T/) of 11 GHz. At a supply voltage of 1.9 V, the measured mixer input third-order intercept point is +2.3 dBm with a 10.9 dB single-sideband noise figure. Power dissipated by the mixer is less than 5 mW. The low-noise amplifier input intercept is -3 dBm with a 2.8 dB noise figure and 9.5 dB gain. Power dissipation of the preamplifier is less than 4 mW, again from a 1.9 V supply.

A new method for determination of single-sideband noise figure

A new method for determining mathematically the single-sideband noise figure of a device from double-sideband measurements is presented. The need for tunable filters as in other single-sideband measurement systems has been eliminated, and hence this method greatly reduces the complexity and cost of performing accurate noise figure measurements. Compared to conventional methods, more noise power measurements are required during both the calibration and measurement stages. These are combined in such a way as to cancel out the unwanted sidebands and are subsequently corrected for mismatch errors. Results obtained at various frequencies for both active and passive test devices with frequency-dependent noise figures are presented and compared to the expected values and the equivalent double-sideband measurements. >

High performance W-band InAlAs-InGaAs-InP HEMTs

0.15 mu m T-gate lattice-matched In/sub 0.52/Al/sub 0.48/As-In/sub 0.53/Ga/sub 0.47/As-InP HEMTs with a device minimum noise figure of 1.7 dB with 7.7 dB associated gain at 93 GHz have been fabricated. A single-ended active mixer was fabricated using these devices, and a conversion gain of 2.4 dB was measured with 7.3 dB single-sideband noise figure at 94 GHz. This is the first reported active mixer conversion gain at W-band.

A high-performance, miniaturized X-band active mixer for DBS receiver application with on-chip IF noise filter

A GaAs monolithic microwave integrated circuit (MMIC) dual-gate FET active mixer at X-band is described that is designed for direct broadcast satellite (DBS) applications. All of the components of the mixer, including biasing circuitry, RF, LO, and IF matching networks, as well as the IF noise filter, are implemented monolithically into a 25-mil*30-mil area. The design was process tolerant, and layout was compact for manufacturability and low cost. The mixer was integrated monolithically into a complete single-chip DBS low-noise block (LNB) converter. The active mixer has a conversion gain of 5.5 dB and a single-sideband noise figure of 8.5 dB. The circuit is manufactured using a 0.5- mu m gate length, buried p/sup -/ depletion mode MESFET process without substrate-through via holes.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Novel method for calculating the noise figure of microwave MESFET mixers

A new computer analysis method is presented by which the noise contributions of the various noise sources within a MESFET mixer can be determined and its overall single sideband and double sideband noise figure and noise temperature calculated. The method extends Kerr's work on diode type mixers and utilises a frequency conversion matrix of a MESFET mixer which was described previously. The simulation program was run for a mixer circuit based on an NEC720 transistor, and the results for the noise sources and noise figure behaviour as functions of the LO power are presented and compared to measured values with good agreement. An optimal operating point from the standpoint of minimum noise figure can thus be determined for transistor biasing conditions and the LO input power.

Glass reinforced GaAs beam lead Schottky diode with airbridge for millimetre wavelengths

We describe the fabrication and measurement of a glass reinforced beam lead Schottky diode with an airbridge for use at millimetre wavelengths. We report an extremely low single sideband (SSB) noise figure for these diodes of 7.9 dB at 94 GHz, including a 1.5 dH IF (30 MHz) contribution.

V-band Low-noise Integrated Circuit Receiver

A compact low-noise V-band integrated circuit receiver has been developed for space communication systems, The receiver accepts an RF input of 60-63 GHz and generates an IF output of 3-6 GHz. A Gunn oscillator at 57 GHz is phaselocked to a low-frequency reference source to achieve high stability and low FM noise. The receiver has an overall single sideband noise figure of less than 10.5 dB and an RF to IF gain of 40 dB over a 3-GHz RF bandwidth. All RF circuits are fabricated in integrated circuits on a Duroid substrate.

A 26-GHz Band Integrated Circuit of a Double-Balanced Mixer and Circulators

Integration of a double-balanced mixer and ferrite-disk type circulators have been successfully achieved in the 26-GHz band. The total single-sideband noise figure of the integrated circuit, composed of a mixer and two circulators, is 8.5 dB, including the noise contribution from an IF amplifier. The double-balanced mixer is composed of microstrip lines, slot lines, coupled slot lines, coplanar lines, Au wires, and four beam lead Schottky-barrier diodes. The minimum conversion loss of the mixer is 5.3 dB at a signal frequency of 25.4 GHz. Isolation between RF and LO ports is greater than 30 dB. The ferrite-disk type circulator is produced by a newly developed precise machining technique. The minimum insertion loss of the circulator is 0.45 dB, and the isolation is greater than 20 dB. The integrated circuit with the ferrite-disk type circulators will be extended to the millimeter-wave band.

Performance and reliability of an improved high-temperature GaAs Schottky junction and native-oxide passivation

We have developed a reliable, high-performance, batch-processed, GaAs tantalum Schottky diode (with a gold overlayer) and native-oxide passivated junction1in a quasi-planar configuration, Varactors and mixers have been fabricated with near-ideal characteristics and state-of-the-art performance. Typically, they exhibit, at 0 V, a junction capacitance near 0.1 pF and a cutoff frequency in excess of 700 GHz when measured at 55 GHz. In a paramp application pumped at 101 GHz, and a signal frequency of 35 GHz, we have obtained a noise figure of 3.5 dB, a gain of 17 dB, and a bandwidth of 600 MHz. When used as frequency doublers (50-100 GHz) and triplers (35-105 GHz), we have realized better than 25-percent efficiency. As mixers, at X band, we achieved a single sideband noise figure of 6 dB and the diodes are typically able to sustain short pulse energy (1.5 × 10-9s) of up to 4.5 ergs with no performance degradation. Reliability tests results to date indicate a MTBF of better than 108h at 100°C and greater than 105h at 200°C. In a commercial application of paramps (3.7-4.2 GHz), these diodes have successfully completed 2.5 million operational varactor hours with no performance degradation.

Millimeter-Wave Thin-Film Downconverter

A 60-GHs hyhrid integrated downconverter intended for use in a mitlimeter-wave radio relay experiment has heen designed and tested. The converter consists of a strip transmission line circuit and two beam-leaded Schottky-barrier diodes which are pumped at a subharmonic of the convectional Iocal oscillator frequency. The conversion loss of the circuit is 6.3 dB and the total single-sideband noise figure, including the noise contribution from the IF amplifier, is 9.1 dB. The circuit looks attractive for millimeter-wave communication systems application up to 100 GHz.

Low-Noise, Integrated, Millimeter-Wave Receiver

A low-noise, hybrid-integrated, millimeter-wave receiver that consists of a local oscillator and a downconverter on a silica substrate is described in this paper. The source for the local oscillator is a Gunn diode, and the mixer element is a beam-leaded Schottky barrier diode. A novel filter circuit is used to combine the local oscillator and the signal with low insertion loss in the signal path. The single-sideband noise figure of the receiver at 30 GHz is 5.5 dB, including 0.8-dB contribution of the if amplifier, and the rms FM frequency variation resulting from the local oscillator is 168 Hz/√KHz.

A 20-GHz Integrated Balanced Mixer

An integrated balanced mixer for use in the receiver for the quasi-millimeter-wave digital radio transmission system is described. The following aspects of the mixer realization are discussed. 1) The characteristics of gallium arsenide Schottky barrier diodes and three types of diode mount construction are described. The least observed dc incremental conversion loss was about 4 dB in the range of 18-23 GHz. 2) The fabrication of waveguide to microstrip transition, using a ridged waveguide transducer, is described. A transition loss of less than 0.38 dB was obtained in the range of 18-21.75 GHz. 3) The microstrip circuit elements, such as the 3-dB directional coupler and the low-pass filter, are described. The minimum isolation and coupling values of the coupler were about 16 dB and 3-4 dB, respectively. 4) The effect of the undesirable electromagnetic mode propagation on the integrated mixer operations is discussed. 5) The performance of the integrated balanced mixer is presented. This mixer, operated at a signal frequency of 20 /spl plus mn/0.5 GHz and at a local oscillator frequency of 18.3 GHz, showed a single side-band noise figure of 4.8-5.8 dB. 6) The reliability of the mixer is also evaluated with high reliability under vibration and shock testing being exhibited.

Low-Noise Microstrip Mixer on a Plastic Substrate (Correspondence)

Design information is given for microstrip on a thin sheet of polyolefin that is reinforced with aluminum. A balanced 6-GHz-mixer-70-MHz-preamplifier design on this material is described. A single sideband noise figure less than 6 dB is obtained over the operating frequency range with no tuning adjustments.

Beam-lead Schottky-barrier diodes for low-noise integrated microwave mixers

This paper describes the fabrication and performance of beam lead <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</tex> on <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n^{+}</tex> silicon-molybdenum, barrier dual Schottky diodes. The fabrication is by a process sequence which allows the use of a single molybdenum gold-metal deposition step for both the Schottky barrier and beam-lead interconnection system. Typical <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I-V</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/C^{2}-V</tex> plots indicate uniformity of barrier heigh and n factor. Values of n less than 1.1 were measured with the barrier height at 0.61 eV. Measurements of change in barrier height with temperature up to 500°C show less than ± 10 mV variation. Dc characteristics of these devices give forward current matching of ± 10 mV at 1 mA. The R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> is 10 ohms and the C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j</inf> is less than 0.3 pF, giving an RC product less than 3 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> seconds. Using these devices in a chrome-gold on alumina microstrip integrated mixer, overall single sideband noise figures of 6.5-7.0 dB were measured, with a 1.5 dB IF noise figure, at 9.4 GHz. Measured noise figure was essentially constant over a range of 1-10 mW of local oscillator power, and the diodes will with stand over 500 mW CW RF power. These values compare favorably with discrete packaged devices. Fabrication in series pairs, matched quads or other configurations can be accomplished with good uniformity.

A Monolithic Single-Ended X-Band Mixer Circuit

A monolithic single-ended X-band mixer circuit has been fabricated on a high-resistivity silicon substrate, employing selective epitaxial deposition. The final resistivities of the N-type substrates are between 5000 and 17000 ohm-cm. The mixer diode is a molybdenum-silicon Schottky barrier diode. The overall single-sideband noise figure for the circuit obtained at 9 GHz was 10.5 dB.

Integrated 4-GHz Balanced Mixer Assembly

A 4-GHz balanced Schottky barrier diode mixer-preamp was designed and fabricated on ceramic substrate and epoxy glass board using both thin-film and printed-circuit technologies. The elements were integrally assembled in a common housing resulting in a compact low-cost receiver with operating characteristics designed to meet the requirements of long-haul high-density transmission systems. A single-sideband noise figure of 6.5 dB was obtained.

Noise Figure and Conversion Loss of the Schottky Barrier Mixer Diode

The theory of mixer operation is briefly reviewed and the results presented in graphical form convenient to the designer. In particular, the minimum noise figure, conversion loss, and the source and output impedances are plotted as functions of the pulse duty ratio of the diode current. Emphasis is placed on the pulse duty ratio as a more fundamental parameter for defining mixer operation than the magnitude of the diode voltage which is generally nonsinusoidal. It is shown that Schottky diode mixers should exhibit single sideband noise figures as low as 3 dB at X band when used in conjunction with 1.5 dB noise figure IF amplifiers, provided the diodes have cutoff frequencies higher than 500 GHz.