Fourier Rotman Lens Enabled Directional Modulation Transmitter

Figure 16

Measured BER results for (a) the DQPSK and (b) the DBPSK type receivers in the dual-beam DM systems. The DQPSK signals and the DBPSK signals with the same power were applied at the 7th and the 9th beam ports of the Fourier Rotman lens, respectively. SNR for each receiver case was set to 25.8 dB and 21.2 dB. The BER responses in the corresponding conventional single-beam DQPSK and DBPSK non-DM systems are also provided.

(a)

(b)