impatt diode การใช้

• The IMPATT diode family includes many different junctions and metal semiconductor devices.
• An IMPATT diode generally is mounted in a microwave package.
• IMPATT diodes have also been fabricated from SiC.
• Tunnel, Gunn and IMPATT diodes exhibit negative resistance, which is useful in microwave and switching circuits.
• Consequently, both the phase shift and the output power is substantially lower than in a IMPATT diode.
• The IMPATT diode operates over a narrow frequency band, and diode internal dimensions must correlate with the desired operating frequency.
• Low-power microwave sources use solid-state devices such as the field-effect transistor ( at least at lower frequencies ), tunnel diodes, Gunn diodes, and IMPATT diodes.
• Devices with this type of negative resistance include the IMPATT diode, UJT, SCRs and other thyristors, electric arc, and gas discharge tubes like thyratron tubes, fluorescent lamps and neon lights.
• A semiconductor diode's current voltage characteristic can be tailored by selecting the semiconductor materials and the radio-frequency oscillations ( tunnel diodes, Gunn diodes, IMPATT diodes ), and to produce light ( light-emitting diodes ).
• Negative resistance in diodes was rediscovered in 1956 in the tunnel diode, and today negative resistance diodes like the Gunn diode and IMPATT diode are used in microwave oscillators and amplifiers and are some of the most widely used sources of microwaves.
• A change to 24 GHz has been suggested as microwave emitters similar to LEDs have been made with very high quantum efficiencies using negative resistance, i . e ., Gunn or IMPATT diodes, and this would be viable for short range links.