Measurement of Efficiency Degradation Due to External Detuning of a Tunable Patch Antenna

摘要

Realistic deployment scenarios for narrow-band mobile terminal antennas can place the antenna in close proximity to sources of detuning such as the user’s hand. Undesirable side effects can include frequency shifts off-resonance and degraded impedance matching, reducing the overall system efficiency. Here,3D radiation patterns and radiated efficiency measurements were used to evaluate the ability of a tunable matching network to preserve system efficiency in a patch antenna detuned with a hand phantom. The results indicated a trend for improving tuner benefit as a function of increasing severity of detuning.However, the transducer efficiency of 69%—which is a major issue in system evaluation—was too low to justify the improved impedance matching with the degree of detuning examined here.