46 results about "Comb generator" patented technology

A jammer for jamming communications in a communications system where the communications system operates with digital bursts having burst periods measured in time and occurring in a communication frequency band such as GSM having a transmit band and a receive band. The jammer includes a tone comb generator for providing repetitions of jamming signals for the communication frequency band where the jamming signals have jamming signal intervals providing frequency separation between the jamming signals. The jamming signals are generated with a dwell time substantially less than a burst period for the communications system. The jamming signals are generated concurrently for the transmit band and the receive band and are transmitted as RF jamming signals to jam communications for mobile stations.

An airborne jammer for transport by an aircraft for jamming communications in a communications system where the communications system operates with digital bursts having burst periods measured in time and occurring in a communication frequency band such as GSM having a transmit band and a receive band. The jammer includes a tone comb generator for providing repetitions of jamming signals for the communication frequency band where the jamming signals have jamming signal intervals providing frequency separation between the jamming signals. The jamming signals are generated with a dwell time substantially less than a burst period for the communications system. The jamming signals are transmitted as RF jamming signals to jam communications for mobile stations.

The invention discloses a method for generating a microwave frequency comb, which belongs to the technical field of microwave photons. First, inject the DC optical signal with adjustable amplitude into the semiconductor laser, so that the semiconductor laser works in a single-cycle oscillation state; then divide the output optical signal of the semiconductor laser into upper and lower paths, and the upper path undergoes photoelectric conversion, delay, and amplification. As a feedback signal, it is re-modulated to the semiconductor laser to form a photoelectric feedback loop; the downstream optical signal is sent to the photodetector for photoelectric conversion; the amplitude of the DC optical signal is modulated so that the amplitude of the DC optical signal is periodic The linear change of the property, and make the delay of the photoelectric feedback loop be an integer multiple of the linear change period of the amplitude of the DC optical signal. At this time, the output of the down channel photodetector is the microwave frequency comb signal. The invention also discloses a microwave frequency comb generating device. The invention can generate a microwave frequency comb signal with large bandwidth, high and fine comb-tooth spacing, and tunable bandwidth, center frequency and comb-tooth spacing.

A comb frequency generator that is tunable to vary the width of the pulses in the output signal and achieve a maximum power output at different harmonic frequencies. A wavefront compression device receives a sinusoidal input signal and provides wavefront compression to create a compressed signal having a series of periodic fast edges. A delay device receives the fast-edge compressed signal and delays the fast-edge signal to create a delayed fast-edge signal. A combining device receives the original fast-edge compressed signal and the delayed fast-edge compressed signal to generate an output signal including a series of pulses having a width determined by the delay of the delayed signal. In one embodiment, the delay device is a shorted transmission line stub having a length selectively set by a series of MEM devices. In another embodiment, the delay device is an NLTL variable time delay device that delays the fast-edge signal.

The invention provides a frequency mixer group delay measuring circuit which comprises a vector network analyzer and a comb generator. The vector network analyzer comprises a first frequency synthesizer, a second frequency synthesizer and a receiver. The output signals of the first frequency synthesizer are divided into two channels through a first coupler, one channel signals are coupled to the radio-frequency signal input end of a frequency mixer to be tested, and the other channel signals are coupled to the receiver. The output signals of the second frequency mixer are coupled to the local oscillating signal input end of the frequency mixer to be tested. The vector network analyzer further comprises a reference oscillator, the output end of the reference oscillator is coupled to the input end of the comb generator, the output end of the comb generator and the output end of the frequency mixer to be tested are coupled to the input end of a second coupler together, and the output end of the second coupler are coupled to the receiver. The frequency mixer group delay measuring circuit can achieve the measurement of the phase position of a measurement channel conveniently and fast, and achieve phase error correction accurately.

A frequency comb generator fabricated on a chip with elimination of a disadvantageous reflow process, includes an ultra-high Q disk resonator having a waveguide that is a part of a wedge structure fabricated from a silicon dioxide layer of the chip. The disk resonator allows generation of a frequency comb with a mode spacing as low as 2.6 GHz and up to 220 GHz. A surface-loss-limited behavior of the disk resonator decouples a strong dependence of pumping threshold on repetition rate.

Techniques are disclosed for eliminating or otherwise sufficiently suppressing spurious signals. The techniques are particularly useful in applications such as those that employ aggressor frequency sources along with a frequency conversion or mixing function, and especially applications implemented as a system-on-chip. In the spur-training mode, a spur-canceller circuit identifies spurious tones associated with the host system to neutralize those tones when running in a normal mode. The tones are neutralized using a comb generator with variable phase and gain by way of cancellation with comb output signals having substantially the same amplitude and a phase that is 180° out of phase with the aggressor tone to be cancelled.

A vectorial network analyzer including n test ports. With the connection of several different calibration standards to the test ports, several calibration measurements are implemented. For the calibration, different measurements are implemented. Initially, in n calibration measurements, a comb-generator signal is supplied via a direct connection successively to all n test ports. Using a measuring point at the output of the comb generator and the measuring point associated with the respective test port, phase measurements are implemented at all of the frequencies forming the comb-generator signal. A frequency-dependent phase offset is determined from the phase measurements. Moreover, in at least one measurement, all n test ports are terminated successively in each case using known, input impedances, identical within one measurement, of arbitrary transmission properties, wherein successively, all n test ports are excited using a transmission oscillator successively with all frequencies of the comb-generator signal.

Apparatus and methods are presented for enhancing the acquisition speed or performance of Fourier domain optical coherence tomography. In preferred embodiments a plurality of wavelength combs containing interleaved selections of wavelengths from a multi-wavelength optical source are generated and projected onto a sample. In certain embodiments the wavelength combs are projected simultaneously onto a plurality of regions of the sample, while in other embodiments the wavelength combs are projected sequentially onto the sample. Light in the wavelength combs reflected or scattered from the sample is detected in a single frame of a sensor array, and the detected light processed to obtain a tomographic profile of the sample. In preferred embodiments the wavelength comb generator comprises a wavelength interleaver in the form of a retro-reflective prism array for imparting different displacements to different selections of wavelengths from the optical source.

A comb frequency generator that is tunable to vary the width of the pulses in the output signal and achieve a maximum power output at different harmonic frequencies. A wavefront compression device receives a sinusoidal input signal and provides wavefront compression to create a compressed signal having a series of periodic fast edges. A delay device receives the fast-edge compressed signal and delays the fast-edge signal to create a delayed fast-edge signal. A combining device receives the original fast-edge compressed signal and the delayed fast-edge compressed signal to generate an output signal including a series of pulses having a width determined by the delay of the delayed signal. In one embodiment, the delay device is a shorted transmission line stub having a length selectively set by a series of MEM devices. In another embodiment, the delay device is an NLTL variable time delay device that delays the fast-edge signal.

The invention discloses an all-optical broadband micro-wave frequency comb generator and relates to the technical field of coupling device of optical waveguide and a photoelectric element. The generator comprises a frequency comb seed resource generating module, an adjusting control module and a frequency spectrum expanding module. The frequency comb seed resource generating module comprises a first semiconductor laser, a first aspherical lens, a first beam splitter, a second beam splitter, a first Faraday rotator, a second Faraday rotator, a first plane mirror and a second plane mirror. The adjusting control module comprises a computer and a piezoceramics. The frequency spectrum expanding module comprises an adjustable attenuator, an opto-isolator, a second aspherical lens and a second semiconductor laser. The all-optical broadband micro-wave frequency comb generator has the advantages that electronic bottleneck is broken, comb distance adjustment is flexible, wide-broadband microwave frequency comb signal is further acquired, and comb lines are balanced in a certain degree.

The current comb generator periodically applies current spikes to a power supply signal in the time domain to produce a series of current spikes at different frequencies in the frequency domain.

An integrated electro-optic frequency comb generator based on ultralow loss integrated, e.g. thin-film lithium niobate, platform, which enables low power consumption comb generation spanning over a wider range of optical frequencies. The comb generator includes an intensity modulator, and at least one phase modulator, which provides a powerful technique to generate a broad high power comb, without using an optical resonator. A compact integrated electro-optic modulator based frequency comb generator, provides the benefits of integrated, e.g. lithium niobate, platform including low waveguide loss, high electro-optic modulation efficiency, small bending radius and flexible microwave design.

An optical comb generator for generating multiple optical wavelengths from a single source simultaneously for many optical channels on a semiconductor substrate. The comb generator provides narrow channel spacing using chirped Bragg grating with uniformly spaced grating pitches but with tapered waveguide to facilitate the fabrication process and generate laser comb channels with uniform line widths across all channels. The laser comb generator facilitates monolithic integration of many photonic integrated circuit elements.