Thermally optimized interdigitated transistor
AssigneeTexas Instruments Incorporated
InventorSamuel D. Pritchett
Life of this patent
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Abstract
A quasi-interdigitated transistor (50) for rf power applications has a plurality of channel regions (102-118) that are each offset from each other in a y-direction such that a q.sub.x heating component from adjacent channel regions will affect any one channel region to a lesser extent that the q.sub.x from adjacent channel regions in the conventional interdigitated structure. In a preferred embodiment, the channel regions (102-118) are formed in a single, curved, V-shaped row such that the cumulative transverse width of all of the transistor sections is less than the waveguide cutoff frequency. The V-shaped row of transistor sections also provides the advantage of parallel signal paths having approximately the same propagation time delay such that there is no phase cancellation within the device.
Claims20
A method of transmitting a high frequency signal comprising the steps of:
- (a) providing an active semiconductor device having a plurality of active semiconductor element sections, each of said element sections having a heat producing region, a small input region and an output region, adjacent ones of said element sections being spaced apart in a first direction and offset in a second direction substantially perpendicular to said first direction, the magnitude of the offset being preselected as a function of said spacing;
- (b) coupling a single high frequency signal to said input regions of each of said active semiconductor element sections;
- (c) altering said high frequency signal in each of said active semiconductor element sections;
- and
- (d) coupling together said output regions of each of said active semiconductor element sections such that the active semiconductor element sections operate as a plurality of parallel components and sum the output of each of said active semiconductor element regions in-phase at said coupled together output regions.
A method of transmitting a high frequency signal comprising the steps of:
- (a) providing a semiconductor substrate;
- (b) forming in said substrate a plurality of active semiconductor elements, each of said elements having an input terminal, an output terminal and a heat producing region having a longest dimension, adjacent ones of said elements being spaced apart in a first direction and offset in a second direction perpendicular to said first direction, the magnitude of said offset being preselected as a function of said spacing;
- and
- (c) coupling together each of said input terminals and coupling together each of said output terminals.
Dependencies are inferred from the claim text.