Showing papers on "IMPATT diode published in 2001"
TL;DR: In this article, the first experimental demonstration of microwave oscillation in 4H-SiC impactionization-avalanche-transit-time (IMPATT) diodes is reported.
Abstract: Silicon carbide (SiC) is an excellent material for high-power and high-frequency applications because of its high critical field, high electron saturation velocity, and high thermal conductivity. In this letter, we report the first experimental demonstration of microwave oscillation in 4H-SiC impact-ionization-avalanche-transit-time (IMPATT) diodes. The prototype devices are single-drift diodes with a high-low doping profile. DC characteristics exhibit hard, sustainable avalanche breakdown, as required for IMPATT operation. Microwave testing is performed in a reduced-height waveguide cavity. Oscillations are observed at 7.75 GHz at a power level of 1 mW.
56 citations
TL;DR: In this article, a single drift p/sup +/-n-n/sup +/ IMPATT diodes have been fabricated and characterised with avalanche breakdown voltages of /spl sim/290 V.
Abstract: 4H-SiC single drift p/sup +/-n-n/sup +/ IMPATT diodes have been fabricated and characterised. The diodes have avalanche breakdown voltages of /spl sim/290 V. Microwave oscillations appeared in X-band at a threshold current of 0.3 A. The maximum output power of 300 mW was measured at an input pulsed current of 0.35 A.
23 citations
15 Oct 2001
TL;DR: In this paper, a W-band fully coherent pulse Doppler radar was developed in the South West Institute of Electronic Technology (SWIET), which has not only good electrical performance, but also other merits such as reduced system construction, good electromagnetic compatibility and high reliability.
Abstract: A W-band fully coherent pulse Doppler radar was developed in the South West Institute of Electronic Technology (SWIET). The fully solid-state radar transceiver is characterized by a coherent frequency source using IMPATT diode /spl times/ 15 frequency multiplier, 4-stages of IMPATT diode inject-locked W-band pulse power amplifiers, millimeter wave power combiner, and low noise heterodyne receiver with one frequency down conversion. It has not only good electrical performance, but also other merits such as reduced system construction, good electromagnetic compatibility and high reliability.
8 citations
04 Jun 2001
TL;DR: In this paper, the authors describe methods for RF parameter stabilization of injection-locked pulsed IMPATT oscillators during a pulse width over a wide locking band used in Science Research Institute "Orion" (Kiev, Ukraine) for developing power pulsed coherent oscillators at an 8mm wavelength for electronic paramagnetic resonant spectrometers.
Abstract: The essential features of power pulsed IMPATT oscillators include variation of diode junction temperature within the pulse width and operation with high pulse bias current density and, as a consequence, the approach of the avalanche resonant diode frequency to the oscillator's operating frequency. These features lead to considerable change in diode RF impedance during the pulse width and, as result, to variation of the output signal amplitude and phase, and thus requirements for high stability of RF parameters cannot be fulfilled for many applications. This paper describes methods for RF parameter stabilization of injection-locked pulsed IMPATT oscillators during a pulse width over a wide locking band used in Science Research Institute "Orion" (Kiev, Ukraine) for developing power pulsed coherent oscillators at an 8-mm wavelength for electronic paramagnetic resonant spectrometers.
2 citations
25 Jun 2001
TL;DR: In this paper, the microwave characteristics of a SiC IMPATT diode are presented, and it is shown that due to the high breakdown field and high electron saturation velocity of silicon carbide (SiC), it is expected to produce microwave power at least 100 times higher than Si or GaAs IMPATT diodes.
Abstract: IMPact-ionization-Avalanche-Transit-Time (IMPATT) diodes are widely used as microwave sources in transmitters in pulsed radar systems. Under pulsed conditions, the peak output power of an IMPATT diode at a given frequency is limited by its underlying material properties. Due to the high breakdown field and high electron saturation velocity of silicon carbide (SiC), a SiC IMPATT diode is expected to produce microwave power at least 100 times higher than Si or GaAs IMPATT diodes. We reported the first demonstration of a SiC IMPATT diode last year. In this work, the microwave characteristics of the diode are presented.
1 citations
04 Jun 2001
TL;DR: In this article, the performance of 2 mm-wave Si-IMATT diodes under sub-harmonic mode operation was investigated and the drift-diffusion model was applied to the numerical calculation of the diode's dynamic performance.
Abstract: Over the past few years, a major field for application of 2 mm wave IMPATT oscillators has developed in the area of sensor systems and compact short range radars. It is therefore important to increase the output power and efficiency of IMPATT diodes at upper mm-wave frequency bands. It has been shown (Swan, 1968; Mouthaan and Rijpert, 1969; Belousov and Novozhylov, 1990) that tuning the second-harmonic mode of operation of IMPATT diodes is one possible way to increase the output power and efficiency of the diodes. The addition of a properly phased second harmonic voltage improves phasing of the RF current relative to the fundamental voltage so as to increase the negative conductance and give an increase in the output power at the fundamental frequency. However, at the mm-wave frequency band, the negative resistance of the diode at the second harmonic is about ten times less than at the fundamental frequency and its value is comparable to the value of the diode parasitic resistance. Thus, the tuned second-harmonic mode operation of the mm-wave IMPATT diodes is not as efficient as at lower frequencies. This paper presents results of investigation of 2 mm-wave Si IMPATT diodes under driving sub-harmonic mode operation. The drift-diffusion model (Belousov et al, 1979) was applied to the numerical calculation of the diode's dynamic performance.
1 citations
01 Oct 2001
TL;DR: In this article, a planar patch antenna is designed and optimized using the Transmission Line Matrix (TLM) method, where the active part is realized by a negative impedance amplifier, here an IMPATT diode, and the antenna patch operates not only as a radiating element but also as a resonator.
Abstract: In this paper we design and optimize a planar patch antenna using the Transmission Line Matrix (TLM) method. The planar antenna is part of a monolithic integrated millimeter-wave emitter on a high resistivity silicon substrate and features a radiation frequency in the 60 GHz range. The active part will be realized by a negative impedance amplifier, here an IMPATT diode. The antenna patch operates not only as a radiating element but also as a resonator. For designing an appropriate patch resonator one important design criterion is the impedance match with the impedance of the IMPATT diode. This represents a very critical requirement due to the low negative resistance level of the IMPATT diode. Therefore a full wave analysis has to be applied to the whole structure including patch and feeding network. The TLM method has proven to be a very powerful and flexible numerical method for the analysis of various planar and three-dimensional topologies, especially useful for the investigation of broadband structures, but yet has not been utilized extensivly for the analysis of radiating structures. It will be shown, how TLM can be used for antenna modeling. The necessary steps for the design of the patch antenna will be demonstrated and results will be validated by comparison with those obtained by a spectral domain method.
10 Sep 2001
TL;DR: In this article, an oscillator module of microstrip design on a silicon double-drift IMPATT diode has been developed, fabricated and tested, which has provided output power of /spl sim/40-50 mW in the 8 mm wavelength range.
Abstract: We have developed, fabricated and tested an oscillator module of microstrip design on a silicon double-drift IMPATT diode. It has provided output power of /spl sim/40-50 mW in the 8 mm wavelength range. IMPATT diode design involves titanium nitride interstitial phases. This provided high quality and heat tolerance of ohmic contacts.
09 Oct 2001
TL;DR: In this article, the authors report the experimental results concerning the oscillator modules intended for the millimeter wavelength range (operating frequency of 30-39.5 GHz) using silicon double-drift IMPATT diodes whose ohmic contacts involved antidiffusion layers based on TiN/sub x/ interstitial phases.
Abstract: We report our experimental results concerning the oscillator modules intended for the millimeter wavelength range (operating frequency of 30-39.5 GHz). They were fabricated. using silicon double-drift IMPATT diodes whose ohmic contacts involved antidiffusion layers based on TiN/sub x/ interstitial phases. The output power of these modules is 10-50 mW.
20 May 2001
TL;DR: In this paper, the design and microwave performance of a novel tunnel diode-based oscillator designed for 5 GHz in a monolithic IC technology was reported. But the design of the oscillator was not discussed.
Abstract: We report on the design and microwave performance of a novel tunnel diode-based oscillator designed for 5 GHz in a monolithic IC technology. The fundamental output power of the oscillator is -18.8 dBm at 4.7 GHz, with second and third harmonic power levels at -43.2 dBm and -40.5 dBm, respectively. Phase noise of -87.0 dBc/Hz at 1 MHz was observed. While output power can be greatly increased by combining the tunnel diode with an integrated transistor, this design offers excellent compactness and low power consumption. In addition, an LNA design for 6 GHz in the same IC technology is presented.
04 Jun 2001
TL;DR: In this article, the authors proposed an approach to the frequency stabilization by OR that makes it promising for using InP Gunn diodes and IMPATT-diodes at over 100 GHz.
Abstract: The suggested approach to the frequency stabilization by OR makes it promising for using InP Gunn diodes and IMPATT diodes at over 100 GHz. In order to prevent mode jumping and to ensure good matching it is advantageous to use the OR with additional restrictions of resonance space. Owing to the high Q -factor of the oscillating circuit, the frequency noise of IMPATT-diodes is reduced to the noise level of Gunn diodes. High long-term stability can be obtained by thermostabilization of the open resonance system.