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Effect of the PCB length to PIFA performance

1 Effect of the PCB length to PIFA performance




As all electrically small antennas, also PIFA’s performance is dependent on
the size of the ground plane beneath the antenna. Usually the length of the
ground plane, thus the phone’s PCB, is seen as the most critical dimension.


The effect of the PCB length to PIFA’s bandwidth and resonant frequency is
demonstrated using simulated results of simple dual-band PIFA antenna. The
lower resonant frequency is approximately 1 GHz and the higher resonance is
above 1.5GHz. Simulated structure is presented in Figure 1. PCB length is
increased from 60 mm to 160 mm with 10 mm step.

[pic]

Figure 1. Simulated PIFA structure


Change in the antenna’s bandwidth on both bands is pres