Low Phase Noise Oscillator Research Articles

Low phase noise oscillator stabilised by high quality factor AFSIW resonators

A novel X-band low phase noise oscillator is proposed by taking advantage of the enhanced quality factor of air-filled substrate integrated waveguide (AFSIW) resonators. A pair of AFSIW resonators is embedded in a feedback loop, which forms a high-selectivity bandpass filter, to greatly reduce the phase noise of a heterojunction FET oscillator. A prototype is designed, fabricated and measured. At an output signal of 9.85 GHz, the phase noise is −146.8 dBc/Hz and the figure of merit is −210.6 dBc/Hz at 1 MHz offset frequency. An improvement of about 10 dB in phase noise performance is obtained compared with published substrate integrated waveguide resonator-based oscillators.

Low Phase-noise Voltage-controlled Oscillator for Wireless Personal Area Networks

Low Phase-noise Voltage-controlled Oscillator for Wireless Personal Area Networks

Pseudo-impulse tail current shaping for phase noise reduction in CMOS LC oscillators

In this paper, a low phase noise oscillator using tail current shaping method is presented. The current shaping is achieved using two paths for current disconnection and current injection, as a result of which, the total tail current is shaped to a sharp and sawtooth waveform, close to an impulse. Each switching transistor is ON only in 22% of an oscillation period, and tail current is mostly supplied to these transistors near the outputs peak points. In those moments, the oscillator sensitivity to noise sources is minimum. The proposed oscillator is designed and simulated in 0.18 μm RF CMOS technology with 1.8 V supply, and using the inductor model offered by the process, with quality factor of 11. Post layout simulations predict an oscillation frequency of 1.65 GHz, and phase noise of −127.7 dBc/Hz at 1 MHz offset, which is 6.3 dB better than that of simple cross coupled oscillator with the same core oscillator power consumption of 2.2 mW. The proposed circuit, however, consumes an extra power of about 1.9 mW for the added current shaping circuits. Compared to conventional tail current shaping technique, the proposed oscillator offers better tail current shaping, and a much higher start-up current and gain, which is desirable.

Low phase noise oscillator based on complementary split‐ring resonators loaded quarter‐mode circular SIW cavity

A high Q -factor substrate integrated waveguide (SIW) cavity resonator and its application of X-band low phase noise oscillator is proposed. Complementary split-ring resonators are used to improve the Q -factor of the proposed resonator. The size of the resonator is reduced by using quarter-mode circular SIW cavity. The oscillator based on the proposed SIW cavity resonator can be easily designed and tested. Measured results demonstrate an output frequency of 10.11 GHz and a phase noise of -108.7 dBc/Hz at 100 kHz offset. The oscillator is also able to deliver an output power of 4.6 dBm and harmonic rejection of better than 30 dBc. The proposed oscillator is suitable for low-cost high-frequency systems.

A Novel Low Phase Noise Oscillator Using Stubs Loaded Nested Split-Ring Resonator

In this letter, a novel low phase noise oscillator based on stubs loaded nested split-ring resonator (SLNSRR) is proposed. The SLNSRR consists of a nested split-ring resonator (NSRR) and two short-circuited stubs loaded symmetrically at the NSRR bottom. It possesses a compact size about $0.094\,\,\lambda _{g} \times 0.129\,\,\lambda _{g}$ (where $\lambda _{g}$ is the guided wavelength at the center frequency). Based on the proposed SLNSRR, a close-to-upper passband transmission zero has been realized in a bandpass filter. The filter has a sharp phase variation and leads to a steep group delay, which can obtain better phase noise performance in an oscillation circuit. For verifying the design, an L-band oscillator has been fabricated and measured. The measured results show that at the oscillation frequency of 1.98 GHz with 9.5-dBm output power, the phase noise is −127.22 and −145.43 dBc/Hz at 100-kHz and 1-MHz frequency offset, respectively. The figure-of-merit at 100-kHz frequency offset is −198.4 dBc/Hz.

Low Phase Noise Frequency Synthesis for Ultrastable $X$ -Band Oscillators

In this letter, the design of a low phase noise frequency synthesizer is presented. The synthesizer was designed to produce four frequencies: 10 MHz, 100 MHz, 1 GHz and 10 GHz. The 1-GHz signal is produced by frequency division whereas the 100-MHz output is generated by phase-locking a low phase noise oscillator to the 1-GHz signal, hence significantly reducing its phase noise. Both residual and total phase noise measurements are presented.

An Alternative Technique to Minimize the Phase Noise of X-band Oscillators Using Improved Group Delay SIW Filters

This letter presents a new method to realize microwave low phase noise oscillators using high selectivity SIW filters. A perturbing via-hole is located inside the dual-mode circular cavity to significantly enhance the filter selectivity. By properly adjusting this perturbing via-hole position, the oscillator phase noise can be minimized at frequency location of the improved group delay peak. Several planar X-band oscillator prototypes have been fabricated and measured. Good agreement between experiment and predicted results is shown. The designed oscillators have advantages of simple design process, planar structure, and improved phase noise. At the oscillation frequency of 10.178 GHz, the measured real phase noise is −135.4 dBc/Hz@1MHz and −1.35 dBm output power.

A Low Power Low Phase Noise Oscillator for MICS Transceivers.

A low-power, low-phase-noise quadrature oscillator for Medical Implantable Communications Service (MICS) transceivers is presented. The proposed quadrature oscillator generates 349~689 MHz I/Q (In-phase and Quadrature) signals covering the MICS band. The oscillator is based on a differential pair with positive feedback. Each delay cell consists of a few transistors enabling lower voltage operation. Since the oscillator is very sensitive to disturbances in the supply voltage and ground, a self-bias circuit for isolating the voltage disturbance is proposed to achieve bias voltages which can track the disturbances from the supply and ground. The oscillation frequency, which is controlled by the bias voltages, is less sensitive to the supply and ground noise, and a low phase noise is achieved. The chip is fabricated in the UMC (United Microelectronics Corporation) 0.18 μm CMOS (Complementary Metal Oxide Semiconductor) process; the core just occupies a 28.5 × 22 μm2 area. The measured phase noise is −108.45 dBc/Hz at a 1 MHz offset with a center frequency of 540 MHz. The gain of the oscillator is 0.309 MHz/mV with a control voltage from 0 V to 1.1 V. The circuit can work with a supply voltage as low as 1.2 V and the power consumption is only 0.46 mW at a 1.8 V supply voltage.

Robust Study and Design of a Low Power CMOS CSVCO using 45nm Technology

This paper consist of the design and detailed study of a three stage Current Starved Voltage Controlled Oscillator having a very low voltage supply of 1V with low phase noise. The Three stage CSVCO is designed. This work is being done on Cadence virtuoso analog and digital IC design tools with gpdk 45nm CMOS technology process. The voltage supply is taken to be 1V which is low and quite useful according to the latest trends. The center frequency is taken to be 2.4 GHz which is best suitable for satellite and many other applications. The proposed CSVCO consumes low power, low area, low phase noise and high oscillation frequency. The design procedure adopted and the simulation results acquired are illustrated. This CSVCO is suitable for a fast locking PLL, for frequency synthesizer, for clock generation and recovery etc. The results obtained are compared with the previous works and improvements are observed. The Phase noise of the proposed CSVCO is less as compared to the other works.

A Dual-Band Low Phase Noise Microwave Oscillator Based on a Novel High Q Complementary Split Ring Resonator

ABSTRACTIn the present article, a dual-band low-phase noise oscillator is designed, constructed, and experimentally verified using a dual-band high group delay complementary split ring resonator. This oscillator is of serial feedback type. Oscillation frequencies have been designed at group delay peak of resonator so as to remarkably reduce the phase noise of an oscillator at two frequency bands. Additionally, the oscillator can be extended to a voltage-controlled-oscillator by attaching a varactor diode on the resonator. The oscillation frequencies of the oscillator in the present article are approximately 4.75 GHz and 5.33 GHz. The oscillator oscillates at only one frequency band in each moment. Oscillation frequency is selected by means of a switch. If the switch is on, oscillation frequency will be 4.75 GHz, the measured phase noise will be around –108 dBc/Hz at offset frequency of 100 KHz, and frequency tuning range with varactor diode voltage variation will be approximately 65 MHz around this oscillation frequency. On the other hand, if the switch is off, oscillation frequency will be 5.33 GHz, the measured phase noise will be around –129 dBc/Hz at offset frequency of 100 KHz, and frequency tuning range with varactor diode voltage variation will be approximately 81 MHz around this oscillation frequency.

A low phase noise microwave oscillator based on a high Q SIW cavity CSRR band-pass filter

This study designed, developed and put empirically into test a low phase noise oscillator using a complementary split ring resonator filter of high Q factor as a frequency stabilization and selection element. This oscillator is of parallel feedback type. The oscillator was designed at the group-delay-peak frequency of the filter to achieve a dramatic reduction in the phase noise of the oscillator. At the oscillation frequency 5.36 GHz, the phase noise was measured −128 at 100 kHz offset frequency and −145 at 1 MHz offset frequency. The designed oscillator revealed the output power 7 dBm. According to the scientific literature, the proposed oscillator was found to enjoy the best performance at low phase noise for planar microwave oscillators.

Ku‐band low phase noise oscillator using the high order mode loaded with L‐slot SIW resonator

ABSTRACTThis article introduces a novel high Q‐factor substrate integrated waveguide (SIW) cavity resonator and its application of Ku‐band low phase noise oscillator. Q‐factor of the proposed resonator is improved by using the L‐slot and the higher order mode. The L‐slot is placed on edge of TE102 mode field. Therefore, the L‐slot has little influence on resonant frequency but can obviously enhance roll‐off characteristic of S11. And the high order modes have the bigger Q value than fundamental mode. The negative resistance oscillator based on the proposed SIW cavity resonator is easily designed and tested. The experimental results of Ku‐band oscillator show outstanding low phase noise of −130.43 dBc/Hz at 1 MHz offset frequency from 15.55 GHz carrier frequency. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2325–2328, 2016

Design of LC Resonator for Low Phase Noise Oscillators

The effects of resonator topology on the phase noise of LC oscillators are studied in this paper. It is shown that there is a neglected factor that can considerably influence the phase noise behavior of the oscillator. We designate this factor as the Inductance Energy Factor (IEF), which directly depends on the topology of the resonator. It is shown that through proper design of the resonator for a better IEF, the oscillator phase noise can be improved. It is also shown that by modifying the resonator structure to improve IEF, the phase noise does not have to be constrained by the minimum realizable inductance and its maximum quality factor. Therefore, the power-phase noise trade-off remains effective beyond this point. In the following, a general method to design the resonator circuit by a so-called evolutionary modification of the conventional LC tank is given. Illustrated simulations further help to confirm that phase noise improvements of more than 10 dB can be readily achieved by judicious design of the resonator circuit.

An optoelectronic oscillator based on series resonance cavity

Commercial and military applications of microwave and millimeter-wave sources in aerospace, radar, navigation, and communication system require high spectrum purity and low phase-noise oscillators. The optoelectronic oscillator (OEO) emerges as an excellent low noise source that has attracted great attention in recent years. In this paper, a novel technique is proposed for single-mode selection in an optoelectronic oscillator, which uses a microwave cavity as the mode selector. It consists of a pump laser and a feedback circuit including an intensity modulator, an optical fiber delay lines, a photodetector, an amplifier, a filter and two drilling cables. The drilling cable is fabricated by drilling open holes on a coaxial cable using a drilling machine. By changing the radius of the drilling holes, the designed reflection coefficient can be obtained. By simulation, the constructed microwave resonator that consists of a filter and two drilling cables has a higher Q value and only the modes that satisfy the oscillation conditions of the loop will be selected. The basic principle is analyzed theoretically and experimentally. By comparing with traditional structure of OEO, it is shown that the novel structure can effectively improve the side-mode suppression ratio. In addition, the stability of the oscillation frequency is easier to control than the parallel structure. In this experiment, the output of a 10 GHz single-mode signal with a side-mode suppression ratio of 72 dB and a phase noise of -122 dBc/Hz@10 kHz from the carrier is obtained. Meanwhile, phase-lock techniques are used to compensate the drift of cavity length. Then the radio frequency (RF) stability of the oscillation frequency is measured using an RF spectrum analyzer, and the RF stability over 3 hours for the OEO is less than 4 Hz. This scheme has the advantages of traditional OEO with low noise since no extra active devices are needed, and it suppresses the side-mode noise also effectively. In addition, this system is promising for the development of compact, high frequency, low cost and low noise OEOs.

A compact low-phase noise oscillator with superior harmonic suppression characteristics based on novel nested split-ring resonator (NSRR)

In this paper, a novel microwave oscillator incorporating miniaturized nested split-ring resonators is proposed. The high-quality (Q) factor and wide spurious-free band of the NSRR contribute to low-phase noise and high-harmonic suppression of the proposed oscillator circuits. In addition, the NSRR is featured by compact size of 0.12λg × 0.12λg, where λg is the guided wavelength of resonance frequency. The fabricated 2.4 GHz oscillator has an output power of 11.7 dBm with 5 V DC supply and 10 mA current consumption. The second harmonic suppression is −45.49 dBc, the phase noise is −110 dBc/Hz @100 kHz, and the DC–RF conversion efficiency is measured as 30%.

C형태의 DGS 공진기를 이용한 초고주파 발진기 설계

Since phase noise is one of the most important parameters in the design of microwave oscillators, several methods have been proposed to reduce the phase noise. These methods have focused on improving the quality factor of resonators, which result in low phase noise oscillators. Dielectric resonators have been widely used for low phase noise in microwave oscillators due to their high quality factor. However this cannot be used in MMIC oscillators because they have a 3D structure. In this paper, to overcome this problem a novel resonator using open ring type DGS is proposed for improvement of phase noise characteristics that is weak point of oscillator using planar type microstrip line resonator, and oscillator for 5.8GHz band is designed using proposed DGS resonator. The open ring type DGS resonator is composed of DGS cell etched on ground plane under microstrip line. At the fundamental frequency of 5.8GHz, 6.1dBm output power and -82.7 dBc@100kHz phase noise have been measured for oscillator with ring type DGS resonator. The phase noise characteristics of oscillator is improved about 96.5dB compared to one using the general microstrip resonator.

X‐band low‐phase noise oscillator employing substrate integrated waveguide dual‐mode filter

A novel low-phase noise oscillator employing a substrate integrated waveguide (SIW) dual-mode bandpass filter as a frequency stabilisation element within its feedback loop is proposed. The SIW dual-mode filter is implemented based on the use of the two degenerate modes (TE102 and TE201) and has a larger group delay peak than the conventional SIW cavity resonator. By taking advantage of the large group delay peak, the phase noise of the oscillator has significant improvement. An X-band oscillator with a GaAs HEMT packaged transistor has been designed and measured. At an oscillation frequency of 9.04 GHz, the measured phase noise is −111.9 dBc/Hz at 100 kHz offset. The output power is 6.1 dBm and the figure of merit is −198 dBc/Hz.

A Low-Voltage CMOS-Microelectromechanical Systems Thermal-Piezoresistive Resonator With $Q > 10\,000$

We report a thermally driven and piezoresistively sensed CMOS-microelectromechanical systems (MEMS) resonator with quality factor Q >10000 and stopband rejection of 15 dB under CMOS-compatible bias voltage. The bias voltage requirement of this letter is two orders of magnitude lower than that of the previous CMOS-MEMS capacitively transduced resonators. In addition, the combination of the bulkmode resonator design and highQ SiO2/polysilicon structural material leads to resonator Q >10000, a key index for low-phasenoise oscillators and low-insertion-loss filters. The resonator with a center frequency at 5.1 MHz was fabricated using a standard 0.35 μm 2-poly-4-metal CMOS process, featuring low cost, batch production, fast turnaround time, easy prototyping, and MEMS/IC integration. To resolve the feedthrough issue often seen in conventional thermal-piezoresistive resonators: 1) separation of the heater and piezoresistor is first adopted because of the routing flexibility of the structural configuration offered by CMOS back-end-of-line materials and 2) fully differential measurement scheme is then applied to the proposed device, both of which enable a low-feedthrough level with 65-dB improvement as compared with its single-ended counterpart.

Low phase noise oscillator based on quarter mode substrate integrated waveguide technique

Low phase noise oscillator based on quarter mode substrate integrated waveguide technique

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

In this letter, we report a low phase noise oscillatorexhibiting state-of-the-art phase noise characteristics at 60 GHz.The oscillator is stabilized by an off-chip substrate integratedwaveguide (SI ...