Abstract: An electronic device may be provided with near-field communications (NFC) circuitry for communicating with external equipment. Test equipment may perform radio-frequency testing on the NFC circuitry. During manufacture of an electronic device having the NFC circuitry, the test equipment may be placed into electrical contact with antenna feed terminals on the NFC circuitry prior to attaching an antenna to the feed terminals so that a conductive path is formed between the test equipment and an NFC transceiver on the NFC circuitry. Test signals may be conveyed between the test equipment and the NFC transceiver over the conductive path for characterizing the performance of the NFC circuitry. The conductive path may include an antenna impedance modeling circuit formed on a circuit board substrate that models the impedance of the antenna that is to be attached to the NFC circuitry to allow for suitable power transfer during testing.

Abstract: An electronic device may be provided with near-field communications (NFC) circuitry for communicating with external equipment. Test equipment may perform radio-frequency testing on the NFC circuitry. During manufacture of an electronic device having the NFC circuitry, the test equipment may be placed into electrical contact with antenna feed terminals on the NFC circuitry prior to attaching an antenna to the feed terminals so that a conductive path is formed between the test equipment and an NFC transceiver on the NFC circuitry. Test signals may be conveyed between the test equipment and the NFC transceiver over the conductive path for characterizing the performance of the NFC circuitry. The conductive path may include an antenna impedance modeling circuit formed on a circuit board substrate that models the impedance of the antenna that is to be attached to the NFC circuitry to allow for suitable power transfer during testing.

Abstract: Methods and systems to synchronize to a remote node counting rate, symbol rate, and carrier frequency as functions of an estimated frequency offset and relationships between the remote node carrier frequency and counting rate, and between the remote node carrier frequency and symbol rate. The carrier frequency offset may be scaled in accordance with a ratio between the carrier frequency and the remote counting rate to synchronize the local counting rate with the remote counting rate, and/or scaled in accordance with a relationship between the carrier frequency and the remote symbol rate to synchronize the local receive path and/or transmit path sample rate with the remote symbol rate. The carrier frequency offset may be applied as compensation in the receive path and/or the transmit path. The remote and local nodes may correspond to a network coordinator and an existing node, respectively, in a Multimedia Over Coax (MoCA) environment.