Low noise microwave oscillator using ultra high Q dielectric resonator

Uzawa, Koichi; Matsumoto, Kazutoshi

doi:10.1109/mwsym.1991.147136

Cited by 10 publications

(5 citation statements)

References 9 publications

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“…Reducing phase noise of a microwave oscillator is still a hot topic. For this purpose, conventional microwave oscillators typically use frequency selection networks (FSNs) with a high quality factor, such as a metal cavity resonator or a dielectric resonator [1][2][3][4], which are mainly applied in a low frequency range. However, these FSNs have disadvantages, such as large size and difficulty in integration when they are applied in RF/Microwave frequency range.…”

Section: Introductionmentioning

confidence: 99%

Substrate-Suspended Air Cavity Resonator and Its Application in Low Phase Noise Oscillator

Yang²,

Huang

et al. 2021

Front. Phys.

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In this paper, we present a substrate-suspended air cavity resonator featuring high-Q, consisting of five separate layers for confining electromagnetic energy. Its field distribution is analyzed in depth. By appropriately coupling the two resonators, a second-order Chebyshev bandpass frequency selection network is obtained, and design procedure is described. It forms a specific group delay response, in which high values can be achieved within a narrow frequency range around the center frequency. The frequency selection network has great flexibility in adjusting its magnitude and phase responses so that low insertion loss and high group delay are achieved simultaneously. This feature plays an important role in reducing phase noise when it is applied in a microwave oscillator. For demonstration, an X-band oscillator example was designed and fabricated. As the measured results show, it works at 11.16 GHz, and the phase noise at 100 KHz away from the oscillation frequency is as low as −120.68 dBc/Hz.

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Section: Introductionmentioning

confidence: 99%

Substrate-Suspended Air Cavity Resonator and Its Application in Low Phase Noise Oscillator

Yang²,

Huang

et al. 2021

Front. Phys.

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“…Up to now, there arise various types of oscillators. Usually, dielectric and cavity resonators with high‐quality factors are adopted in classic oscillators . However, they are somewhat bulky and not planar so that they are not easy to be integrated with other planar circuits and implemented in integrated circuits.…”

Section: Introductionmentioning

confidence: 99%

Low phase noise L‐band oscillators based on novel general Chebyshev bandpass filters

Xiao

Cao

2019

Circuit Theory & Apps

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Oscillators act as signal sources for wireless communication systems, radars, wireless charging, and other industrial applications, whose phase noises directly determine system performance. In this paper, two low-phase noise microwave oscillators based on novel microstrip second-order band-pass filters are presented. These filters are characterized by good frequency selectivity owing to two transmission zeros near to the passbands. As a result, relatively high group delay can be achieved at center frequencies, which is vital to the phase noise performance of the oscillators to be designed. Simultaneously, the bandwidths can be made narrow enough so that actual oscillating frequency is very close to the designed one. In addition, the introduction of stepped impedance makes these filters capable of harmonic suppression, which efficiently suppresses the harmonics in the output such as the second harmonic. These filters are compact and also of easy design. Finally, two microwave oscillators at 2.0 GHz are designed on these microstrip filters. As the measured results show, their output frequencies are 2.002 GHz. The phase noises are −127.21 and −127.03 dBc/Hz@100 kHz, respectively. The second harmonic suppressions are as great as 30.45 and 39.21 dBc, respectively. KEYWORDS group delay, harmonic suppression, microstrip filter, microwave oscillator phase noise | INTRODUCTIONOscillators usually act as signal sources for wireless communication systems, radars, wireless charging systems, and other industrial applications. Their phase noises directly determine system performance. It is necessary to develop oscillators with low-phase noise. Up to now, there arise various types of oscillators. Usually, dielectric and cavity resonators with high-quality factors are adopted in classic oscillators. 1-4 However, they are somewhat bulky and not planar so that they are not easy to be integrated with other planar circuits and implemented in integrated circuits.As the well-known Leeson model shows, the loaded quality factor Q L of the frequency selection network play an important role in the phase noise performance of oscillators. 5 Recently, to use band-pass filters as frequency selection network within the feedback loop of oscillators receives much attention. By creating transmission zeros near the passbands of band-pass filters, it is likely to achieve group delay peak at oscillating frequency so that high quality factor is available for reduction of phase noise of oscillators. For example, 6,7 apply four-pole elliptic band-pass filters as frequency stabilization elements within microwave oscillators to reduce phase noise. In Chang and Tseng, 8 a trisection filter with a transmission zero near the passband is utilized to design a low-phase noise oscillator. Chao-Hsiung and Chih-Lin 9 uses

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“…Among these, the use of the high-resonator, such as dielectric resonator (DR), is most widely employed in microwave oscillator and shows reliable results [1], [2]. However, since such a high-resonator is composed of different material and has a three-dimensional (3-D) shape, it requires a separate process for its placement on the circuit.…”

Section: Introductionmentioning

confidence: 99%

“…2 is the response of the active filter measured with 10-dBm input power. It shows 20 MHz of 3-dB bandwidth [loaded of 500 by (2)]. This value is beyond the limit of the resonator's unloaded .…”

Section: Introductionmentioning

confidence: 99%

A phase noise reduction technique in microwave oscillator using high-Q active filter

Lee

Nam

2002

IEEE Microw. Wireless Compon. Lett.

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This letter presents a 10-GHz oscillator that uses a high-active filter to reduce the phase noise. The loaded of active filter is obtained at about 500. This oscillator is compared with another oscillator which uses a passive filter. The difference of two oscillators' is estimated at 12.5 times the open-loop gain simulation. The measured result of phase noise at 100-kHz offset shows maximum 10-dB reduction with high-active filter.

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Low noise microwave oscillator using ultra high Q dielectric resonator

Cited by 10 publications

References 9 publications

Substrate-Suspended Air Cavity Resonator and Its Application in Low Phase Noise Oscillator

Substrate-Suspended Air Cavity Resonator and Its Application in Low Phase Noise Oscillator

Low phase noise L‐band oscillators based on novel general Chebyshev bandpass filters

A phase noise reduction technique in microwave oscillator using high-Q active filter

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