Follow the links to read the full papers in the IET Digital Library.
A method to reduce coaxial cavity resonator size using zeroth order resonance (ZOR) characteristics is demonstrated in work from Korea. Introducing air-core coils inside a conventional coaxial cavity resonator is shown to give it ZOR characteristics and a 30% reduction in size is achieved. The resonator still exhibits reasonable unloaded Q factor making the ZOR duplexer a possible substitute for expensive and heavy conventional designs.
Researchers in China present a terahertz FSS filter for application in atmospheric remote sensing by satellite. The filter transmits TE and TM polarized signals for a 45° incident wave centred at 0.448 THz, a typical sounding point of water, and suppresses four discrete bands over the frequency range of 0.177 – 0.396 THz. The maximum tested loss is less than 0.4 dB, making it suitable for the design requirements of a front-end quasi-optical receiver.
Crossing the silicon
Researchers in Japan have used a cutting edge lithography technique to fabricate Si wire array waveguide grating wavelength demultiplexers. They achieved a record breaking crosstalk floor of -23 dB, so the technology can be used in optical interconnections, which are finding increasing use in data centres, and also in future consumer electronics.
Made by history
The first study of the dynamics of trapping effects in AlGaN/GaN HEMTs using specific pulsed I-V characterizations to determine current collapse and drain lag emission/capture times depending on the electrical history on the device has been presented by researchers in France. Their findings may have a great impact on power performance, especially under pulsed mode operation, as is the case for radar applications.
A method for the identification of devices in a mobile or wireless network by means of their radiofrequency ‘fingerprints’ is presented in research from Spain. The method allows easy identification of authorised and unauthorised devices, which could be used to control access to a network.