Most of the link uses 4 and 6 GHz. Short term fading in microwave communication links can be overcome by diversity reception and transmission.Ionosphere propagation is not possible in micro wave communication because it penetrate through ionosphere. In microwave communication links, the rain drop attenuation experienced is mainly due to absorption of microwave energy by …
Microwave devices
E plane tee – axis of its side arm is parallel to the electric field in the main branch.E arm is also called series arm and main arm is called collinear arm. If fields of same magnitude and phase are entered through the opposite sides of main arm then net field in the side arm …
FET & JFET
FET FET has square law characteristics. It has negative temperature coefficient. High immunity against radiation. FET has least noise. Pinch off voltage of FET is 5 volt. FET is classified in to JFET ( junction field effect transistor) and MOSFET (metal oxide semiconductor FET). MOSFET has highest input impedance. Quiescent current of FET is ID. …
Carrier telephony
Carrier is generated by high precision, temperature controlled crystal oscillator, operates at a frequency 124 KHz. Output of this master oscillator is feed to harmonic generator, which supplies super group carrier frequencies. Required harmonics are selected by filters. 124 KHz frequency is subdivided into 4 KHz. This 4 KHz is then used in odd and …
Audio power amplifiers, Single stage transistor amplifier & Multistage amplifier
Audio power amplifiers Power amplifiers handles large signals (not very large). Size of power transistor is large, to dissipate heat. Tuned amplifier is used in RF application. Class A power amplifier uses one transistor, this transistor never turn off which is its main disadvantage. Driver stage commonly uses class A. Class A amplifier is most …