RF/microwave components

A radio communication system is a wireless communication system in which the transmission channel comprises a radio frequency channel wherein the radio frequency channel is defined by a range of frequencies of the electromagnetic frequency spectrum. Radio communications systems offer a number of significant advantages over wired communications systems. High frequency radio frequency (RF) communications are becoming more and more prevalent in the world today. Radio frequency (RF) communication modules are commonly used in wireless communication devices such as cellular phones. Microwave communication systems rely on a plurality of radio frequency and microwave components such as RF power amplifiers, power splitters and combiners, modulators and demodulators, frequency converters, transformers and oscillators, and etc, that are combined to form communications apparatus such as RF transmitters, receivers, and base stations to transmit and receive data. Most wireless communication devices use transceivers (transmitters and receivers) that have an intermediate frequency (IF) stage between the baseband and the radio frequency (RF) stages. A transmitter operative in a radio communication system converts the communication signal to be transmitted into a form suitable for transmission thereof upon the radio frequency channel. An RF transmitter mixes the desired signal, known as the baseband signal, with an RF carrier frequency for transmission over the selected medium. The transmitter portion of a radio communication device includes a power amplifier to amplify the RF signals before they are coupled to the antenna for transmission. In a typical RF receiver the RF signal is received by an antenna, then amplified using a fixed gain amplifier and transmitted over a transmission line having a characteristic impedance to the receiver circuitry. Radio frequency (RF) receivers are used in a wide variety of applications such as television, cellular phones, pagers, global positioning system (GPS) receivers, cable modems, cordless phones, radios and other devices that receive RF signals. Antennas and antenna systems are utilized with radio frequency transmission and reception devices for communications and control. Antennas transmit and receive electromagnetic waves made of a combination of electric and magnetic fields propagating in a certain direction. One type of antenna that is commonly used in space based applications is a parabolic antenna. Parabolic reflector antennas are typically used to redirect a ground based signal either to another satellite or to another ground based receiving station.