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.

The present application discloses a radio frequency system, includes a detection device, at least one antenna line device, and an antenna that are sequentially connected in series by using a radio frequency channel. Each of the at least one antenna line device is configured to: receive a detection signal from the detection device or a previous antenna line device connected in series to the antenna line device; and add device information of the antenna line device to the received detection signal, and send, to the antenna or a next antenna line device connected in series to the antenna line device, the detection signal to which the device information is added. The detection device obtain device information of each of devices connected in series on a radio frequency line, to determine whether a connection relationship between the devices is correct, and determine a specific port location at which an error occurs.

The present application discloses a radio frequency system, includes a detection device, at least one antenna line device, and an antenna that are sequentially connected in series by using a radio frequency channel. Each of the at least one antenna line device is configured to: receive a detection signal from the detection device or a previous antenna line device connected in series to the antenna line device; and add device information of the antenna line device to the received detection signal, and send, to the antenna or a next antenna line device connected in series to the antenna line device, the detection signal to which the device information is added. The detection device obtain device information of each of devices connected in series on a radio frequency line, to determine whether a connection relationship between the devices is correct, and determine a specific port location at which an error occurs.

A testing device may receive, via a receiving port of a radio frequency (RF) frontend of the testing device, a downlink pilot signal, and may determine a phase associated with the downlink pilot signal. The testing device may transmit, via a transmitting port of the RF frontend of the testing device, an uplink pilot signal. The testing device may receive, after transmitting the uplink pilot signal, the uplink pilot signal via the receiving port of the RF frontend of the testing device. The testing device may determine, after receiving the uplink pilot signal, a phase associated with the uplink pilot signal. The testing device may adjust, based on a phase difference between the phase of the downlink pilot signal and the phase of the uplink pilot signal, one or more transmission settings of the testing device.

Antenna monitoring modules associated with antennas and test antennas communicating test signals, input blocking modules, and addressable mixed signal processors determining antenna performance. Distributed antenna systems including global transceivers, splitters or tappers, monitoring modules, antennas and test antennas, that monitor antenna presence and performance indications, and centrally report antenna status.. Distributed antenna systems including a trunk, multiple coupled branch runs with corresponding antenna monitoring modules, antennas and switches, capable of io selectively decoupling antennas. Distributed antenna systems with programmable attenuators for adjusting transmission levels for a trunk and its segments, branches, and corresponding antennas. Distributed antenna systems for over the air antenna transmission and reception testing using local or global signals. Distributed antenna systems with a system controller selectively depowering and repowering segments is thereof. Distributed antenna systems with switches coupled to an antenna monitoring module by multiple selectable routes. Distributed antenna systems with loop-based antenna configurations supplying power in multiple directions.

A vehicle-to-X communication system having a vehicle-to-X communication module. The vehicle-to-X communication module continuously carries out self-tests which are based on receiving test messages and evaluating test messages in order to recognize errors.

A vehicle-to-X communication system having a vehicle-to-X communication module. The vehicle-to-X communication module continuously carries out self-tests which are based on receiving test messages and evaluating test messages in order to recognize errors.

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.

Techniques are provided which may be implemented using various methods and/or apparatuses in a mobile device to address maximum permissible exposure (MPE) proximity sensor failure. A mobile device may include a maximum permissible exposure (MPE) sensor control unit to actively monitor signals associated with proper operation of the MPE proximity sensors. Upon detecting an anomaly in any of these signals, such as a value drop below a given threshold, an MPE sensor control Unit will inform an AP (application processor, or other processor or controller) which in turn trigger display of a warning message on the display of the mobile device or the issuance of other warnings such an audible or tactile alert to inform the end user about the maximum permissible exposure (MPE) proximity sensor malfunction and/or notify the end use of a condition resulting in deactivation of the 5G new radio transceiver.