Methods and apparatus for reducing and/or canceling signal interference between receiver and transmitter components of a wireless communications device are described. The methods and apparatus are well-suited for use in a wide range of devices including user equipment devices such as cell phones as well as in network equipment such as base stations. Opto-mechanical devices are used in some embodiments as part of an apparatus which performs interference cancelation on RF (Radio Frequency) signals.

Methods and apparatus for interference cancelation in a radio frequency communications device are described. In various embodiments a signal to be transmitted in converted into an optical signal and processed using an optical filter assembly including one or more optical filters to generate an optical interference cancelation signal. The optical interference cancelation signal is converted into an analog radio frequency interference cancelation signal using an optical to electrical converter prior to the analog radio frequency interference cancelation signal being combined with a received signal to cancel interference, e.g., self interference. The optical filter assembly can include a large number of taps, e.g., 30, 50, 100 or more. Each tap may be implemented as a separate optical filter or series of optical filters. Delays and/or gain of the optical filters can be controlled dynamically based on channel estimates which may change due to changes in the environment and/or communications device position.

Methods and apparatus for reducing and/or canceling signal interference between receiver and transmitter components of a wireless communications device are described. The methods and apparatus are well suited for use in a wide range of devices including user equipment devices such as cell phones as well as in network equipment such a base stations. Opto-mechanical devices are used in some embodiments as part of an apparatus which performs interference cancelation on RF (Radio Frequency) signals.

Disclosed herein is a swappable modular-based radiofrequency (RF) frontend that is reconfigurable to form transmitting (TX) and receiving (RX) phased array systems for diverse applications. Such swappable RF frontend may be used with unique spatial and spectral optical processing of complex RF signals over an ultra-wide frequency band. The swappable RF front end may be used in conjunction with an optically upconverted imaging receiver and/or in conjunction with optically addressed phased array technologies transmitters.

A tunable multi-mode laser is configured to generate a multi-mode optical signal at a tuned wavelength. The laser includes a semiconductor optical gain region, a feedback region, and a phase modulation region between the gain and feedback regions. Each of the regions may be monolithically integrated. A feedback loop is coupled to the tunable laser to receive the optical signal and includes at least one delay line. The delay line may also be monolithically integrated. An output of the delay line is fed back to the tunable multi-mode laser in order to provide at least one of self-injection locking and self-phase locked looping for the multi-mode tunable laser. Each of the optical gain region and phase modulation region of the laser is biased by the output of the delay line in order to reduce phase drift of the optical signal.

High-performance ultra-wideband Phased Array Antennas (PAA) are disclosed, having unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for PAA systems are enabled by photonic integration and ultra-low-loss waveguides. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors, providing the capability to combine many RF photonic signals with very low loss. Architectures include tunable optical up-conversion and down-conversion systems, moving a chosen frequency band between baseband and a high RF frequency band with high dynamic range. Simultaneous multi-channel RF beamforming is achieved through power combining/splitting of optical signals.

Device, methods and systems for the electronic demodulation of optically phase demodulated signals are described. An example optical local oscillator generator configured to generate a radio frequency (RF) tone at a desired RF frequency includes a first input configured to receive a broadband optical pulse train, a second input coupled to a delay line interferometer to receive a first control voltage for controlling a delay value of the interferometer and to produce an output optical pulse train, a dispersive element, coupled to the delay line interferometer, to map the output optical pulse train to a time-domain modulated optical pulse train, an optical-to-electrical converter, coupled to the dispersive element, to convert the time-domain modulated optical pulse train to an analog electrical signal, and an RF filter, coupled to the optical-to-electrical converter, to filter the analog electrical signal to generate the RF tone at the desired RF frequency.

An optic reference signal generator comprising a housing forming an enclosed space with one or more air flow openings. Within the housing is an optic signal generator driver configured to generate an optic signal generator drive signal. An optic signal generator generates an optic signal responsive to the optic signal generator drive signal. A polarity control unit adjusts polarization of the optic signal to create a polarization adjusted optic signal and a modulator bias generator and controller generates a modulation signal. A pattern signal input receives a pattern signal and a modulator receives the polarization adjusted optic signal, the pattern signal, and the modulation signal to generate a modulated output signal.

A wireless signal transmitter and a wireless signal receiver are provided. The wireless signal transmitter includes an optical signal generation region that generates excitation light by beating two optical signals that have different wavelengths and that are output through different laser diodes, and a wireless signal generation region that modulates the excitation light output from the optical signal generation region into a wireless signal with a carrier frequency of a terahertz band, using a photomixer. The optical signal generation region and the wireless signal generation region may be connected by a multimode optical fiber to reduce a nonlinear effect occurring in an optical fiber. Also, the wireless signal receiver includes a signal processor, for example, an equalizer, for compensating for a modal dispersion, and may compensate for a modal dispersion caused by the multimode optical fiber used in the wireless signal transmitter.

Provided is a phased array antenna which can be used in the millimeter wave band and whose cost is lower than that of a conventional phased array antenna. The phased array antenna (1) includes: an optical modulator (OM) configured to generate a signal light beam SL by carrying out intensity modulation on a carrier light beam CL by use of a sum signal V.sub.IF+LO(t), the sum signal V.sub.IF+LO(t) being obtained by adding an intermediate frequency signal V.sub.IF(t) and a local signal V.sub.LO(t); and a time delay device (TD) configured to generate delayed signal light beams SL′1, SL′2, . . . and SL′n by imparting time delays Δt1, Δt2, . . . and Δtn to the signal light beam SL. Each feeding circuit (Fi) generates, from a corresponding delayed signal light beam SL′i, a delayed radio frequency signal V.sub.RF(t−Δti) to be supplied to an antenna element (Ai).