Methods and apparatus are provided for detection path design for reflection coefficient estimation. In one novel aspect, a hardware-based phase estimator estimates a phase shift between the forward path signal and the reverse path signal. In one embodiment, a data selector is used to pass only signals above a magnitude threshold. In another embodiment, a modified phase unwrap algorithm stores an unwrapping correction for subsequent samples and updates the stored unwrapping correction upon processing of each sample processed. In another novel aspect, mixed hardware and software solutions are used. In one embodiment, the reference signal and the detection signals are matched such that the modulation signal interference is removed. In some embodiments, one or two power detectors and a cross-correlator are used. In yet another embodiment, two detection measurement paths are used to obtain the reflection coefficient. In one embodiment, fractional timing offset is estimated to obtain the reflection coefficient.

Methods and apparatus are provided for detection path design for reflection coefficient estimation. In one novel aspect, a hardware-based phase estimator estimates a phase shift between the forward path signal and the reverse path signal. In one embodiment, a data selector is used to pass only signals above a magnitude threshold. In another embodiment, a modified phase unwrap algorithm stores an unwrapping correction for subsequent samples and updates the stored unwrapping correction upon processing of each sample processed. In another novel aspect, mixed hardware and software solutions are used. In one embodiment, the reference signal and the detection signals are matched such that the modulation signal interference is removed. In some embodiments, one or two power detectors and a cross-correlator are used. In yet another embodiment, two detection measurement paths are used to obtain the reflection coefficient. In one embodiment, fractional timing offset is estimated to obtain the reflection coefficient.

An apparatus comprises a radio frequency (RF) antenna circuit; an antenna aperture tuning circuit; an antenna impedance measurement circuit; and a processor circuit electrically coupled to the tunable antenna aperture circuit and the impedance measurement circuit. The processor circuit is configured to: set the antenna aperture tuning circuit to an antenna aperture tuning state according to one or more parameters of an RF communication network; initiate an antenna impedance measurement; and change the antenna aperture tuning state to an antenna aperture tuning state indicated by the antenna impedance.

A system and method for on-wing test of an aircraft transponder involves configuring a self-test feature to the transponder's corresponding onboard ACAS to verify the on-board transponder system conforms to each of a plurality of required tests of an aviation oversight authority standard for operation. Once this test is initiated, the ACAS initiates this transponder test interrogating the transponder via a low power signal causing the transponder to reply accordingly. The ACAS performs each required test to ensure proper transponder function and alerts a user with a failure indication and stores each result should the transponder fail any of the plurality of tests.

A system and method for real-time in-situ calibration of an Active Electronically Scanned Array (AESA) utilizes an S-parameter matrix-based EM transfer function between an end fire, unobtrusive, near field probe radiating element to minimize AESA look angle blockage. A sniffer probe is integrated in the AESA aperture of mechanical mounting frame or embedded with the AESA aperture structure. Hadamard orthogonal coding is utilized to simultaneously energize AESA elements.

A system and method for real-time in-situ calibration of an Active Electronically Scanned Array (AESA) utilizes an S-parameter matrix-based EM transfer function between an end fire, unobtrusive, near field probe radiating element to minimize AESA look angle blockage. A sniffer probe is integrated in the AESA aperture of mechanical mounting frame or embedded with the AESA aperture structure. Hadamard orthogonal coding is utilized to simultaneously energize AESA elements.

A configuration for a wireless device to perform iterations of SIM to detect clutter echo in order to improve a configuration for SIM. The apparatus performs a SIM for multiple beam pairs based on a first transmission power. The apparatus performs an iteration of the SIM for one or more beam pairs that meet a criteria. The iteration of the SIM is based on a second transmission power. The second transmission power is greater than the first transmission power.

An apparatus, method and work product is disclosed. The method comprises measuring plural transmit signals and corresponding receive signals and determining, using a model describing a relation between each of the plural transmit signals and a respective passive intermodulation signal, a standardized passive intermodulation signal as one or more nth order intermodulation products for a standardized transmit signal consisting of two tones each of a power of substantially 20 Watts. The method may also comprise identifying in the model one or more n.sup.th order cross-intermodulation products resulting from three or more transmit signals having different respective carrier frequencies. Responsive to the identification, the method may comprise adapting the standardized two-tone passive intermodulation signal by determining an offset for producing an adapted two-tone standardized passive intermodulation signal, n is an odd integer greater than two.

An apparatus, method and work product is disclosed. The method comprises measuring plural transmit signals and corresponding receive signals and determining, using a model describing a relation between each of the plural transmit signals and a respective passive intermodulation signal, a standardized passive intermodulation signal as one or more nth order intermodulation products for a standardized transmit signal consisting of two tones each of a power of substantially 20 Watts. The method may also comprise identifying in the model one or more n.sup.th order cross-intermodulation products resulting from three or more transmit signals having different respective carrier frequencies. Responsive to the identification, the method may comprise adapting the standardized two-tone passive intermodulation signal by determining an offset for producing an adapted two-tone standardized passive intermodulation signal, n is an odd integer greater than two.

A wireless data communication radio includes a first transceiver configured to be coupled to a first antenna, and a second transceiver configured to be coupled to a second antenna. The second transceiver includes a multi-path detector. The wireless data communication radio transmits a radio signal via the first transceiver, receives the radio signal at the second transceiver, and determines, by the multi-path detector, that the radio signal, as received by the second transceiver, was transmitted by the first antenna and received by second antenna.