Abstract: The embodiments of the present invention include a bias circuit for a power-amplifying device, which receives and amplifies an input RF signal having a series of RF cycles within a modulation envelop. The bias circuit compensates odd-order distortion processes by detecting the power in the input signal and providing a dynamic adjustment to a bias stimulus for the power-amplifying device within a time scale of the modulation envelope.

Abstract: The embodiments of the present invention include a bias circuit for a power-amplifying device, which receives and amplifies an input RF signal having a series of RF cycles within a modulation envelop. The bias circuit compensates odd-order distortion processes by detecting the power in the input signal and providing a dynamic adjustment to a bias stimulus for the power-amplifying device within a time scale of the modulation envelope.

Abstract: A solution of hydrogen peroxide [H.sub.2 O.sub.2 ], citric acid [HOC(CH.sub.2 COOH).sub.2 COOH.H.sub.2 O], and a salt of citric acid such as potassium citrate [HOC(CH.sub.2 COOK).sub.2 COOK.H.sub.2 O], and hydrogen peroxide [H.sub.2 O.sub.2 ], in a proper pH range, selectively etches GaAs-containing Group III-V compounds in the presence of other Group III-V compounds. As an illustration, Al.sub.y Ga.sub.1-y As is selectively etched in the presence of Al.sub.x Ga.sub.1-x As (0.ltoreq.y<0.2 & x>0.2) when the pH range of the etchant solution is between approximately 3 and 6. The etchant solution described herein may be utilized in the fabrication of, for example, high-frequency transistors exhibiting improved saturated current (I.sub.dss) and threshold voltage (V.sub.th) uniformity.

Abstract: Disclosed is a method of forming a uniform length gate electrode and contact for a microwave field-effect transistor where the gate electrode has a length of less than one micron. A photoresist plug is formed on the surface of a first photoresist layer, the plug functioning as a shadow mask in the subsequent deposition of a plasma-etch-resistant material (aluminum) over the surface of the plug and the first photoresist layer. A third photoresist layer is formed over the device structure whereby a contact region can be formed on the surface of the semiconductor sub-strate adjacent to the device region. Subsequently, the third photoresist layer is removed, and the previously shielded photoresist material over the gate electrode location is removed by plasma etch using the metal-covered plug and metal-covered first photoresist layer as a plasma-etch shield.

Abstract: A solution of hydrogen peroxide ?H.sub.2 O.sub.2 !, citric acid ?HOC(CH.sub.2 COOH).sub.2 COOH.H.sub.2 O!, and a salt of citric acid such as potassium citrate ?HOC(CH.sub.2 COOK).sub.2 COOK.H.sub.2 O!, and hydrogen peroxide ?H.sub.2 O.sub.2 !, in a proper pH range, selectively etches GaAs-containing Group III-V compounds in the presence of other Group III-V compounds. As an illustration, Al.sub.y Ga.sub.1-y As is selectively etched in the presence of Al.sub.x Ga.sub.1-x As (0.ltoreq.y<0.2 & x>0.2) when the pH range of the etchant solution is between approximately 3 and 6. The etchant solution described herein may be utilized in the fabrication of, for example, high-frequency transistors exhibiting improved saturated current (I.sub.dss) and threshold voltage (V.sub.th) uniformity.