The development of transparent radio-frequency electronics has been limited, until recently, by the lack of suitable materials. Naturally thin and transparent graphene may lead to disruptive innovations in such applications. Here, we realize optically transparent broadband absorbers operating in the millimetre wave regime achieved by stacking graphene bearing quartz substrates on a ground plate...

iran is located in a roughly triangular deforming region, consisting of relatively undeformed shield areas to the southwest (arabia) and northeast and the more recently deformed, though currently inactive, southwest afghanistan block in the east. the current geological and tectonic setting of iran is due to the ongoing convergence between the arabian and eurasian plates, which resulted in the f...

The first observations to detect a population of distant galaxies directly in the submillimetre waveband have recently been made using the new Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). The results indicate that a large number of distant galaxies are radiating strongly in this waveband. Here we discuss their significance for source confusion i...

We present the design and simulation of a planar Bull’s eye antenna that can simultaneously produce four orbital angular momentum (OAM) modes with up to 2.4 GHz impedance bandwidth at 60 GHz. OAM modes l = ±3, ±13 are produced simultaneously by two ring resonators in the centre of the antenna. The peak gain is 13.1 (8.1) dBi at ±10 (±25) degrees for mode l = ±3 (±13), with all modes present ove...

Nowadays, electromagnetic metamaterials is a rapidly growing research domain involving electromagnetism, microwave and millimetre wave technology, optics, material technology and nanotechnology. In particular, paper concerns about the utilization of split ring resonators in negative permeability meta materials, the concept and the production of an isotropic negative permeability medium, an isot...

Microstrip antennas are one of the most widely used types of antennas in the microwave frequency range, and they are often used in the millimeter-wave frequency range. Actually as the demand for high data rates grows and microwave frequency bands become congested, the millimeter-wave spectrum is becoming increasingly attractive for emerging wireless applications. The abundance of bandwidth and ...