High spectral purity oscillator at 40 GHz: Design using air-dielectric cavity (original) (raw)

PM noise of a 40 GHz air-dielectric cavity oscillator

We describe the design of a low-phase-modulated (PM) noise, 40 GHz oscillator that uses a conventional air-dielectric cavity resonator as a frequency discriminator to improve the PM noise of a commercial 10 GHz dielectric resonator oscillator (DRO) frequency multiplied by four. The main features of this design incorporate (1) unloaded cavity quality factor (Q) of 30,000, (2) high coupling coefficient, (3) large carrier suppression by use of interferometric signal processing, (4) large operating signal power of approximately 1 watt (W), and (5) relatively small size. In addition, we report the PM noise of several Ka-band components.

A 40 GHz Air-Dielectric Cavity Oscillator with Low Phase Modulation Noise

NCSLI Measure, 2014

We describe a 40 GHz cavity stabilized oscillator (CSO) that uses an air-dielectric cavity resonator as a frequency discriminator to reduce the phase modulation (PM) noise of a commercial 10 GHz dielectric resonator oscillator (DRO) frequency multiplied by four. Low PM noise and small size were the main design goals. Single sideband (SSB) PM noise equal to-128 dBc/Hz at a 10 kHz offset from the carrier frequency is achieved for the CSO. In addition, we report on the PM noise of several Ka-band components.

High spectral purity microwave oscillator: design using conventional air-dielectric cavity

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000

We report exceptionally low PM and AM noise levels from a microwave oscillator that uses a conventional airdielectric cavity resonator as a frequency discriminator. Our approach is to increase the discriminator's intrinsic signal-tonoise ratio by use of a high-power carrier signal to interrogate an optimally coupled cavity, while the high-level of the carrier is suppressed before the phase detector. We developed and tested an accurate model of the expected PM noise that indicates, among other things, that a conventional air-dielectric resonator of moderate Q will exhibit less discriminator noise in this approach than do more esoteric and expensive dielectric resonators tuned to a high-order, high-Q mode and driven at the dielectric's optimum power.

Ultra-Low-Noise Cavity-Stabilized Microwave Reference Oscillator Using an Air-Dielectric RESONATOR1

Ultra-low-noise microwave oscillators are often required to serve as reference signals in precision phase modulation (PM) noise measurement systems and in a host of other applications. We have significantly improved the spectral purity of NIST's traditional cavity-stabilized microwave oscillator design, which uses a conventional air-dielectric cavity resonator as a frequency discriminator. We developed and tested an accurate model of the expected PM noise that indicates, among other things, that a conventional air-dielectric resonator of moderate Q will exhibit less discriminator noise than more esoteric and expensive dielectric resonators tuned to a high-order, high-Q mode and driven at the dielectric's optimum power. Additionally, we increase the discriminator's intrinsic signal- to-noise ratio by use of a high-power carrier signal to interrogate an optimally coupled cavity, while the high level of the carrier is suppressed before the phase detector. We report excep...

Dielectric resonator oscillator design and realization at 4.25 GHz

2011

In this paper design and realization of dielectric resonator oscillator operating 4.25 GHz is explained. The oscillator is designed as a negative resistance oscillator where chip-amplifier is used as the negative resistance by adding feedback. The dielectric resonator is simulated using High Frequency Structure Simulator. The simulation and realization results are discussed.

Modeling of a 10GHz Dielectric Resonator Oscillator in ADS

Oscillators are basic microwave energy sources for all microwave communication systems. This paper will discuss the theory and the design of a low phase noise 10GHz parallel feedback GaAs PHEMT dielectric resonator oscillator. The coupling coefficient between the dielectric resonator and the parallel microstrip lines are represented in the form of double coil transformer, while the dielectric resonator is modeled as a parallel RLC component. The coupling gap can be adjusted to optimize the ratio of the loaded to the unloaded quality factor to give a better phase noise. An optimum low phase noise can be achieved when an insertion loss of 9.5dB is obtained. The dielectric resonator oscillator model design was simulated using Agilent ADS software, where at 10GHz exhibited an insertion loss of 8.562 dB with a phase noise of -105.283 dBc/Hz at 100 klHz frequency offset. The output power was exhibited at +15.551 dBm. are also included in . The QL/QO ratio can be varied by adjusting the coupling gap between the dielectric resonator and the microstrip line, of which in this case is represented in the form of turn ratio of transformer which located between the input and the output feedline of the microstrip resonator. This is realized by incorporating a planar EM software called Advanced Design System from Agilent. It is known that the bigger the turn ratio, the closer the gap between the dielectric resonator and the microstrip line. 40

Development and measurement of 10 GHz oscillators with ultra-low phase noise

Microwave and Optical Technology Letters, 2009

This work describes the development of 10-GHz feedback oscillators with ultra-low phase noise. Measurement procedures involving injection locking, composition with synchronized sources and vibrational isolation are described. The application is for gravitational waves detectors. The phase-noise performance obtained was Ϫ100 dBc/Hz at 3 kHz, which is still 45 dB worse than the goal performance.

Low Phase Noise Oscillator at 60 GHz Stabilized by a Substrate Integrated Cavity Resonator in LTCC

IEEE Microwave and Wireless Components Letters, 2014

In this letter we report a low phase noise oscillator exhibiting state-of-the-art phase noise characteristics at 60 GHz. The oscillator is stabilized by an off-chip substrate integrated waveguide (SIW) cavity resonator, manufactured in LTCC technology. The area on top of the cavity resonator is used to flipchip mount the MMIC, realized in SiGe technology. Measured oscillators discussed in this paper operate at frequencies of 59.91 GHz, 59.97 GHz and 59.98 GHz. The measured phase noise at 1 MHz offset is −115.76 dBc/Hz, −115.92 dBc/Hz and −116.41 dBc/Hz, respectively. To our knowledge, the present hybrid oscillator has the lowest phase noise and highest figure of merit of integrated oscillators at V-band. The simulations are in very good agreement with the measured oscillation frequencies.