A frequency reconfigurable antenna may include at least two antenna segments and a photonic crystal positioned between the at least two antenna segments. In accordance with some embodiments a common control channel is used for communicating control signals between the wireless microphone receiver and one or more wireless microphone transmitters, while separate audio data channels are used to carry audio data traffic from each individual wireless microphone transmitter to the microphone receiver. Therefore, a lifespan of the OLED display apparatus is improved. The mixture of fluids can then be further emulsified by passing it over a plurality of obstructions, such as a threaded interior surface of the primary passage, located within the primary passage downstream of the inlet. The flexible sheet is mounted to the housing and provides a front face of the electronic device. Due to a resonance effect of the organic electroluminescent device, the emission efficiency of wavelengths of light of different colors is improved, and high-purity quality pictures may be displayed on the organic electroluminescent device.