Method for identifying self-generated spurious signals

摘要

A local oscillator (LO) of a test system is set to an initial frequency whereupon a device under test (DUT) transmits a radio frequency (RF) signal to the test system. Characteristics of the RF signal are measured with the test system and used to identify magnitudes and frequencies of spurious signal products. The LO of the test system is reset to one or more subsequent frequencies that are offset from the initial frequency. One or more subsequent RF signals are transmitted from the DUT to the test system, with the DUT maintaining its original signal settings. Characteristics of the subsequent RF signals are measured with the test system and used to identify magnitudes and frequencies of spurious signal products for each of the subsequent LO frequencies. The spurious signal products that have shifted in frequency for each of the subsequent LO frequencies as self-generated signal products can then be identified.

主权项

1. A method for identifying self-generated spurious signals comprising:
setting a local oscillator of a test system to an initial frequency; transmitting a radio frequency (RF) signal from a device under test (DUT) to the test system; measuring the physical analog characteristics of the RF signal with the test system; converting the analog values of the measured physical characteristics into first digital equivalents; identifying spurious signal products in accordance with said first digital equivalents; identifying the magnitudes and frequencies of the spurious signal products; resetting the local oscillator of the test system to one or more subsequent frequencies that are offset from the initial frequency; transmitting one or more subsequent RF signals from the DUT to the test system, wherein the DUT maintains the original physical signal settings; measuring respective physical analog characteristics of the one or more subsequent RF signals with the test system; converting the analog values of the measured respective physical characteristics into second or more digital equivalents for each of the one or more subsequent LO frequencies; identifying spurious signal products for each of the one or more subsequent LO frequencies in accordance with said second or more digital equivalents; identifying the magnitudes and frequencies of the spurious signal products for each of the one or more subsequent LO frequencies; and identifying the spurious signal products that have shifted in frequency for each of the one or more subsequent LO frequencies as self-generated signal products.