Injection Locking of Klystron Oscillators

If certain criteria are met, a microwave oscillator may be synchronized by the injection of a controlling signal into the oscillator cavity. Synchronization is dependent upon oscillator circuit parameters, the ratio of injected power to oscillator power, and frequency difference between the free-running oscillator and the injection signal. Locking has been observed with injection signals 70 db below the oscillator output and 30-db ratios have been demonstrated to be easily realizable. Injection locking may be considered a form of amplification that permits taking advantage of the fact that microwave oscillators are smafler, lighter, less expensive and more efficient than amplifier devices. The low-frequency theory of Adler is shown to describe accurately the locking phenomena in reflex klystron oscillators and the transient response is extended to determine limitations on the amplification of modulated signals. Experimental verification of the theory is shown for 180/spl deg/ phase modulation of the locking signal at rates up to 100 kc for a VA-201 klystron. Design relations and curves are presented and applications and improvements are discussed.     

Synchronization Effects in a Submillimeter Josephson Self-Oscillator

We present an experimental and theoretical study of injection locking in an oscillator in the presence of noise. The experiment is performed with a Josephson point-contact self-oscillator heterodyne receiver irradiated by a very weak = 1-THz signal. A general calculation of the oscillator response at low injection level is made based on the theoretical treatment of Stratonovitch. We show that the Josephson oscillator described by the RSJ model obeys the general locking equation in the presence of noise. We assume a simple evolution law of the oscillator spectrum as a fnnction of detuning and calculate its response. The experimental results are compared with computer calculations and the implications are discussed.     

Demonstration of a 311-GHz Fundamental Oscillator Using InP HBT Technology

In this paper, a sub-millimeter-wave HBT oscillator is reported. The oscillator uses a single-emitter 0.3 m15 m InP HBT device with maximum frequency of oscillation greater than 500 GHz. The passive components of the oscillator are realized in a two metal process with benzocyclobutene used as the primary transmission line dielectric. The oscillator is implemented in a common base topology due to its inherent instability. The design includes an on-chip resonator, output matching circuitry, and injection locking port. A free-running frequency of 311.6 GHz has been measured by down-converting the signal. Additionally, injection locking has been successfully demonstrated with up to 17.8 dB of injection-locking gain. This is the first fundamental HBT oscillator operating above 300 GHz.     

A Beam-Steering Antenna Array Using Injection Locked Coupled Oscillators With Self-Tuning of Oscillator Free-Running Frequencies

The analysis and experimental results of an antenna array using injection locked coupled oscillators with self-tuning of oscillator free-running frequencies are presented. With the use of coupled type-II phase locked loops for tuning oscillator free-running frequencies and an external injection signal for stabilizing the array operating frequency, this antenna array can steer its beam through a single control voltage and hold its output frequency at the injection signal frequency in operation. In addition, its beam-pointing error arising from phase errors in coupled oscillators can be reduced and the array works well over a certain frequency band. Phase dynamics and stability are studied and experimentally verified. Experimental results of a three-element injection locked coupled oscillator array show that its uniform phase progression ranges between $-$16 $^{circ}$ and 52$^{circ}$ , and the phase errors are less than 5 $^{circ}$ at 2.7 GHz. The operation bandwidth is shown from 2.68–2.72 GHz. By loading the injection locked coupled oscillator array with rectangular patch antennas, the beam-steering radiation characteristics are measured at various control voltages.      

Computer simulation of Adler's generalized equation for the interaction of oscillators with injected signals

A computer simulation that solves Adler's generalized equation describing the interaction of an injected signal with a free running oscillator is presented [1]. The simulation, performed on a digital computer, offers the advantage of a fast turn-around, great flexibility, and a high degree of accuracy. In contrast to analog computer simulations, no scaling is required. The simulation is demonstrated by determining the injection locking properties of an avalanche diode oscillator and of a pulsed magnetron with injected CW signals. The results concerning avalanche diode oscillator injection locking are in good agreement with other computational methods reported in current literature. The injection locking simulation of pulsed magnetrons, the results of the simulation, appear to confirm experimental data reported in the literature.     

Noise-reduction techniques of high-frequency oscillator-high- order multipliers and avalanche-diode-type microwave sources

Results of noise-reduction techniques by injection phase locking to a master oscillator and through the use of high-Q cavities are presented for a class of high- frequency oscillator-high-order multiplier and avalanche-diode oscillator microwave sources. Frequency and amplitude noise spectra are described for two states of oscillation: free-running and injection phase-locked for the video range 300 hertz to 10 MHz off the carrier frequency. At X band, a rms noise deviation less than 0.15 hertz in a 100-hertz bandwidth has been achieved at frequencies greater than 10 kHz off the carrier for the free-running high- frequency oscillator-high-order multiplier source. Corresponding results obtained for a free-running avalanche- diode oscillator was a flat 6-hertz spectrum across the video range 1 kHz to 100 kHz.     

Frequency synthesiser architecture eliminating high speed frequency dividers for millimetre-wave applications

A frequency synthesiser architecture for millimetre-wave applications is proposed. The architecture is based on a triple-push oscillator, which functions both as a divider and oscillator. Thus, the proposed architecture eliminates the need for injection locked frequency dividers that are the main contributors to the limited tuning capability of millimetre- wave phase-locked loops. Since the proposed architecture is solely based on the performance of the triple-push oscillator, the measurement result of the first silicon triple-push oscillator at 30 GHz is presented to support the validity of the concept.     

Gunn oscillator injection locking circuit at millimeter wave frequencies

Millimeter wave frequencies are proposed as carriers of microcell future mobile systems. High frequencies in the region of 60–62 Ghz are suggested. A serious difficulty in this context is the lack of sufficient gain in active devices. Both on receiver and transmitter units this difficulty is faced. Mixing, amplification, carrier recovery and modulation / demodulation subsytems are required to be operational at these higher frequencies. Presently the MMIC 's show also limited performance. In this report an alternative approach active processing technique is examined based on an injection locking in Gunn oscillator. A non-linear analysis is applied to determine the fundamental properties of injection locking in Gunn oscillator performance under the influence of an external signal. Details of waveguide action is taken into account by solving the corresponding boundary condition problem. Finally experimental results are presented for a 30GHz oscillator.     

Multi-Modulus LC Injection-Locked Frequency Dividers Using Single-Ended Injection

A new wide-locking range multi-modulus LC-tank injection locked frequency divider (ILFD) is proposed and was fabricated in a 0.18 $mu {rm m}$ CMOS process. The ILFD circuit is realized with a complementary MOS LC-tank oscillator and an injection composite composed of an inductor in series with an injection MOS. The two output terminals of the injection composite are connected to the resonator outputs. The ILFD can be used as a first-harmonic oscillator (ILO), even-modulo or odd-modulo oscillator depending upon the incident frequency of injection signal. At the supply voltage of 1.5 V, the free-running frequency is from 4.85 to 5.13 GHz, the current and power consumption of the divider without buffers are 2.78 and 4.17 mW, respectively. At the incident power of 0 dBm, the locking range in the divide-by-1(2, 3, 4) mode is from the incident frequency 3.72 to 8.69 (8.42 to 10.95, 13.66 to 16.03, 19.13 to 20.5) GHz.      

Quantum-well SEED optical oscillators

Oscillation at 110 MHz in a GaAs-GaAlAs quantum-well SEED (self-electrooptic effect device) optical oscillator is considered. Optimization of device length and optical pump wavelength for high-frequency oscillation is discussed. Frequency tuning is obtained by adjusting the oscillator bias voltage or optical pump power, and the oscillator can be injection locked to modulated optical signals. Frequency fluctuations caused by perturbative Gaussian noise and 1/f frequency noise are observed; the 1/f noise in an 8.5-MHz oscillator limited the minimum frequency variance to 230 Hz²     

Intermodulation in an f.m. oscillator injection locked by an f.m. signal

Analysis of injection locking by f.m. signals is presented when the locked oscillator and the locking source are frequency modulated by the same signal. Intermodulation noise and optimum deviation of the locked oscillator are derived, assuming f.m. by band-limited Gaussion noise. Previous published results and recent experiments confirm the results obtained.     

Cavity Stabilization and Electronic Tuning of a Millimeter-Wave IMPATT Diode Oscillator by Parametric Interaction

A new technique is proposed by which both noise reduction and electronic tuning of a millimeter-wave solid-state oscillator can be realized by injecting an arbitrary low-frequency (several hundred megahertz or beyond) signal to the oscillator element which is provided with an additional high-Q cavity. This method has much wider tuning bandwidth than that of the conventional subharmordc injection locking technique. Presented are both experimental results and some theoretical interpretations by using an IMPATT diode oscillator.     

Direct optical frequency modulation and injection locking of resonant tunnel diode oscillator

Preliminary results indicate that a resonant tunnel diode (RTD) oscillator can be optically tuned, frequency modulated, and injection locked. Experiments were performed in which a 2.8 GHz RTD oscillator was frequency modulated from DC to 100 MHz and injection locked over a 150 kHz bandwidth with a laser diode via fibre optics.<>     

W-band gunn second subharmonically locked oscillator

In this paper, the averaging method is used to analyse the performance of second subharmonically injection locked Gunn oscillator. Some useful expressions such as the locking range, output response, output impedance of nonlinear device in fundamental and subharmonic frequency are obtained. a W — band subharmonically locked Gunn oscillator is developed and experimental result demonstrates the validity of this analysis.     

Single longitudinal mode operation of a CO2TEA laser by injection locking with a tunable CO2waveguide laser

A CO2TEA laser was frequency tuned by means of injection locking with a tunable waveguide laser as master oscillator, using a special injection method. Injection-locking experiments were performed at different operating conditions and varying parameters such as laser lines, master oscillator power, and frequency offset from the line center.     

Highly Stable, Low Noise Millimeter-Wave IMPATT Oscillator (Technical Notes)

A highly stable and low noise IMPATT oscillator at 75 GHz is realized by using the parametric injection locking technique along with an AFC circuit in which a crystal oscillator is used as a reference. Noise level of this oscillator is lower by 25 dB compared with that of the free-running IMPATT oscillator, and the frequency stability is as good as 10/sup -8/ /spl deg/C.     

Highly Stable, Low Noise Millimeter-Wave IMPATT Oscillator (Technical Notes)l

A highly stable and low noise IMPATT oscillator at 75 GHz is realized by using the parametric injection locking technique along with an AFC circuit in which a crystal oscillator is used as a reference. Noise level of this oscillator is lower by 25 dB as compared with that of the free-running IMPATT oscillator and the frequency stability is as good as 10/sup -8/ / /spl deg/C.     

New implementation of injection locked technique and its application to low phase noise quadrature oscillators

A new implementation of the injection locked technique is proposed. The incident signal is directly injected into the common-source connection node of the sub-harmonic oscillator instead of the gate of the tail current source, and a narrowband noise filtering network is inserted into the same node to suppress the tail current source noise. A novel quadrature oscillator with the proposed injection locked technique is presented. The simulations show that the phase noise of the quadrature oscillator is about 7 dB better than that of the stand-alone sub-harmonic oscillator. The quadrature oscillator has been implemented in 0.25 um CMOS process and the measured results show that the proposed quadrature oscillator could achieve a phase noise of −130 dBc/Hz at 1 MHz offset from 1.13 GHz carrier while only drawing an 8.0 mA current from the 2.5 V power supply.     

An LO architecture with novel wide locking range,quadrature output RILFDs and ILROs for cognitive radio applications

In this paper, a wide locking range, quadrature output ring type injection locked frequency divider (ILFD) is presented for division ratios of 3 and 4. This ILFD proposes a novel injection scheme that shapes the injection signal to a proper form and provides a convenient situation for divider locking. Furthermore, two new wide locking range, low power consumption, injection locked ring oscillators (ILROs) are proposed for quadrature generation in local oscillator architectures. A novel cognitive radio quadrature local oscillator (LO) architecture is presented by utilizing the proposed ILFDs and ILROs to verify the effectiveness of the proposed circuits. Moreover, a new technique is implemented on the LO architecture to widen the frequency range without consuming any extra power. Because of using a single LC tank, this architecture is very compact. Also, it has the benefit of low power consumption and low output phase noise.     

Analysis of Oscillator Injection Locking Through Phase-Domain Impulse-Response

This paper presents a novel approach to the analysis of oscillator injection locking due to weak external signals. From the intuitive concept of impulse-sensitivity function, a phase-domain macromodel is deduced which is able to capture high-order synchronization effects. Novel closed-form expressions for the synchronization regions are thus presented. The proposed phase-domain macromodel and the expressions derived for synchronization-regions are very general since they apply to any oscillator topology.