Power Combiners Using Two Gunn Diodes for the 3-CM Band
TL;DR: In this paper, the performance characteristics of two-diode power combiner in 3 cm band using Gunn diodes were investigated for combining efficiency, tuning range, voltage co-efficient, frequency drift, external Q and FM noise.
Abstract: Experimental results on the performance characteristics are presented for three configurations of two-diode power combiner in 3 cm band using Gunn diodes. Results are presented for combining efficiency, tuning range, voltage co-efficient, frequency drift, external Q and FM noise. It is found that the combiners may be used to obtain about double the power given by the individual diodes without causing any serious deterioration in the other characteristics. One particular configuration has better performance in respect of tuning range and associated factors, while another configuration has small tuning range but better noise performance.
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TL;DR: In this article, a four-diode X-band Gunn diode combiner is described, and performance characteristics are presented for combining efficiency, tuning range, pushing fire, frequency drift, external Q, and FM noise.
Abstract: A four-diode X-band Gunn diode combiner is described, and the performance characteristics are presented for combining efficiency, tuning range, pushing fire, frequency drift, external Q, and FM noise.
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References
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TL;DR: In this paper, a noise measuring system with a high degree of flexibility in regard to video frequency coverage as well as radio frequency coverage was described for S, X, and Ku-bands.
Abstract: This paper describes a noise measuring system with a high degree of flexibility in regard to video frequency coverage as well as radio frequency coverage. Noise systems for S, X, and Ku-bands were constructed to obtain high sensitivity at spectral frequencies from several Hz to 30 MHz off the carrier. The measured limiting sensitivities of the X-band set over the video range 20 Hz to 325 kHz with an input power of 10 mW are --145 dB for AM noise and 0.02 Hz rms for FM noise in a 100-Hz measuring bandwidth.
81 citations
TL;DR: In this paper, a negative-resistance oscillator with a multiple-resonant circuit was evaluated in terms of effective available noise power densities of both 1/f and white noise sources, an effective saturation factor, and an appropriate Q/sub L/ of the oscillator.
Abstract: Equations are presented that express noise-to-carrier ratio and rms frequency deviation of a negative-resistance oscillator with a multiple-resonant circuit in terms of effective available noise power densities of both 1/f and white-noise sources, an effective saturation factor, and an appropriate Q/sub L/ of the oscillator. Experimental evaluation of the noise parameters in Gunn and avalanche oscillators by use of these equations is described. AM and FM noise measurements have been made on X-band Gunn oscillators and Si and GaAs avalanche oscillators for frequency off carriers extending from 1 kHz to 10 MHz. Both 1/f and white noise have been observed in these oscillators. The validity of the above equations has been verified for Gunn oscillators from the dependence of the noise spectra on Q/sub L/. For Gunn oscillators and Si and GaAs avalanche oscillators, the effective noise-temperature ratio for white noise, N/kT/sub 0/, has been found to be 23~29, 41~51, and 38~44 dB, and the effective saturation factor to be 2~2.9, 0.5~2.4, and 2, respectively. An increase of N/kT/sub 0/ with the RF voltage across the diode has been observed in Si avalanche oscillators. Parameters for 1/f noise have also been evaluated approximately.
37 citations
TL;DR: In this article, it is shown that it is possible to obtain an electronic tuning range of over 1 GHz at X band with an appreciable output power level, which is also nearly constant with frequency.
Abstract: Some results on X-band varactor-tuned Gunn oscillators in a full-height waveguide cavity are presented. It is shown that it is possible to obtain an electronic tuning range of over 1 GHz at X band with an appreciable output power level, which is also nearly constant with frequency. Results of FM noise measurements on one such oscillator are also reported.
14 citations
TL;DR: In this article, the problem of electronic tuning of microwave osciilator structures characterized by high energy storage and hence low noise is considered, and analytical criteria are presented which determine the position of the varactor diode and the theoretical maximum tuning range available including Varactor loss.
Abstract: The problem of electronic tuning of microwave osciilator structures characterized by high energy storage and hence low noise is considered. The evolution of a wide-band varactor tuned J-band oscillator is described, and analytical criteria are presented which determine the position of the varactor diode and the theoretical maximum tuning range available including Varactor loss. Experimental results confirm the validity of the circuit model used for the proposed oscillator structures.
12 citations