Title :
Passive Intermodulation Distortion in Antennas
Author :
Wilkerson, Jonathan R. ; Kilgore, Ian M. ; Gard, Kevin G. ; Steer, Michael B.
Author_Institution :
Dept. of Electr. & Comput. Eng., North Carolina State Univ., Raleigh, NC, USA
Abstract :
An analytic formulation of passive intermodulation distortion (PIM) in antennas is presented for PIM introduced by electro-thermal modulation of conductivity by current-related losses. A silver rectangular patch antenna was fabricated using a sapphire substrate isolating the thermal process from other possible sources. Two-tone testing at 990 MHz using a sweep of the tone separation from 3 Hz to 100 kHz is reported. Both transmitted and reflected PIM are characterized using a high dynamic range two-tone test system incorporating an analog canceler achieving a dynamic range of 125 dB at 1-Hz tone separation for reflection measurements, and 100 dB at 10-Hz tone separation for transmission measurements with each tone set to 32.3 dBm.
Keywords :
UHF antennas; intermodulation distortion; microstrip antennas; analog canceler; current-related losses; dynamic range two-tone test system; electrothermal modulation; frequency 3 Hz to 100 kHz; frequency 990 MHz; passive intermodulation distortion; reflected PIM; reflection measurements; sapphire substrate; silver rectangular patch antenna; thermal process; tone separation; transmission measurements; transmitted PIM; two-tone testing; Conductivity; Current density; Feeds; Heating; Metals; Substrates; Antenna distortion; intermodulation distortion; microstrip patch antenna; nonlinear distortion; passive intermodulation distortion (PIM); two-tone test;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2014.2379947
