Theses diodes can work as photodetector and are used to generate electricity. · Point contact diodes - The construction of this diode is simpler and are used in analog applications and as a detector in radio receivers. This diode is built of n - type semiconductor and few conducting metals placed to be in contact with the semiconductor diode will operate as an efficient mixer, with a bias of only about 200 mV p-p and a signal of 40 mV p-p. Also, if the LO drive is increased to a point where the Schottky diode is driven into forward conduction, it also becomes an efficient mixer. The use of a dc bias, as shown in Fig. 4, permits the Schottky diode to operate with less LO drive. IMPATT Diode as oscillator 6. The IMPATT diode family includes many different junctions and metal semiconductor devices. The first IMPATT oscillation was obtained from a simple silicon p-n junction diode biased into a reverse avalanche break down and mounted in a microwave cavity. 7. Electron-hole pairs are generated in the high field region. 13 special diodes schottky diodes i .overview of the diode schottky diodes are constructed of a metal-to-n junction rather than a p-n semiconductor junction. also known as hot-carrier diodes, schottky diodes are characterized by fast switching times (low reverse-recovery time), low forward voltage drop (typically 0.25 to 0.4 volts for a metal-silicon junction), and low junction capacitance. Gallium arsenide Gunn diodes are made for frequencies up to 200 GHz, gallium nitride materials can reach up to 3 terahertz The electronic band structure of some semiconductor materials, including gallium arsenide (GaAs), have another energy band or sub-band in addition to the valence and conduction bands which are usually used in semiconductor devices. 6.PROCEDURE: Set the components and equipments as shown in the block diagram. Initially set the variable attenuator for maximum attenuation 6. Curve from F to G:- The diode charges up again like a fixed capacitor. At point G the diode current goes to zero for half a period and the voltage remain constant at voltage V A until the current comes back on the cycle repeats. 1.4 Point-contact diodes These work the same as the junction semiconductor diodes, but their construction is simpler.