International Journal

This paper presents a solution to reduce the feed complexity and to improve the total efficiency of X-band compact choke horn antenna with circular polarization and isoflux pattern. This kind of antenna had been designed before by our laboratory for nanosatellite applications, but it required a 4-way divider with phase shifter which generates the insertion losses and therefore a lower realized gai

To incorporate two different communication standards in a single device, a compact triple-band antenna is proposed in this paper. The proposed antenna is formed by etching an inverted L-shaped slot on the patch with defected ground structure. The antenna is targeted to excite three separate bands first from 2.39?2.51, second from 3.15?3.91, and third from 4.91?6.08 GHz that covers entire Wireless

In this paper, a three layered stacked circularly polarized rectangular dual band microstrip antenna with a defected ground structure (DGS) and a feed network with stub (showing dual wideband characteristic) is designed, fabricated, and tested for WLAN, Zig bee, Wi-Max, and IMT band applications. The proposed antenna is fabricated on an FR4 substrate with dielectric constant (?) of 4.4; tan? of 0.

In this paper, an amplitude shift keying (ASK) demodulator with 100% modulation depth is proposed. In order to achieve the higher power and wider reading range the designed ASK demodulator works in the ultra-high frequency. In this design, the average detector and voltage divider are used in order to define the appropriate threshold voltage level for the radio frequency input signal which leads to

A 10 × 10 ?m SiGe heterojunction bipolar photo-transistor (HPT) is fabricated using a commercial technological process of 80 GHz SiGe bipolar transistors (HBT). Its technology and structure are first briefly described. Its optimal opto-microwave dynamic performance is then analyzed versus voltage biasing conditions for opto-microwave continuous wave measurements. The optimal biasing points are the

In this paper, a new kind of admittance inverter and design of a switchable microstrip bandpass filter using composite right/left-handed (CRLH) cells has been presented. The proposed filter has two states (or passbands). One of the two passbands, is accessible at each time by on/off state of three PIN diodes. This filter is a three-pole, coupled resonator filter, composed of short-circuited shunt

The growing demand for communication systems requires multi-channel solutions. However, the number of antennas in communication systems is dictated by the number of channels in each system which is limited by the available space on a broadcasting platform and by the limited available resources. We have developed a Multi-Channel Phase Control coupler in the VHF frequency range enabling a reduction

An ultra-wideband (UWB) frequency-selective surface (FSS) exhibiting band rejection characteristic is presented in this paper. The proposed unit cell has the size of 14 × 14 mm which is approximately 0.18 × 0.18 ?, where ? corresponds to free space wavelength at the lower cut-off frequency. The proposed UWB FSS consists of a single-layer substrate and provides 20 dB attenuation level for a wide ba