An IMPATT diode (IMPact ionization Avalanche Transit-Time) is a form of high power diode used in high-frequency electronics and microwave devices. They are typically made with silicon carbide owing to their high breakdown fields. Types of diodes A diode can be thought of as the electronic version of a one-way valve. ... Silicon carbide (SiC), also known as carborundum or moissanite, is a ceramic compound of silicon and carbon. ...
They operate at frequencies between about 3 and 100 GHz or more. A main advantage is their high power capability. These diodes are used in a variety of applications from low power radar systems to alarms. A major drawback of using IMPATT diodes is the high level of phase noise they generate. This results from the statistical nature of the avalanche process. Nevertheless these diodes make excellent microwave generators for many applications.
A diode according to claim 1, characterized in that said means (9) is adapted to cause an avalanche breakdown at a voltage across said electrodes (1, 2) being a factor of less than 50% of the breakdown voltage of the diode would the active-layer doping be substantially constant across the entire active region thickness.
A diode according to claim 9, characterized in that the lateral separation of said thin layer (9) from the periphery of the diode is larger than the distance between said thin layer (9) and said junction (8), i.e.
A diode according to claims 1, characterized in that it is composed of an array of small sub-diodes (14) with the characteristics defined mounted in parallel and laterally spaced onto a common heat sink (15).
Diode 102 typically has a lead 104 for receiving an injection signal and a lead 106, which is now in connection with switch 108 which has leads 110 extending to an antenna 112 and leads 114 extending to a resistive load 116.
IMPATTdiode 302 is regulated by modulator 310 which is controlled by logic circuit 312 having an input lead 314 to transmission trigger 316.
IMPATT modulators 504, 506, 508 further having output leads to junctions 514, 516 and 518, respectively, which are separated from ground by IMPATTdiodes 524, 526 and 528, respectively.
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