Abstract: The present application relates to methods of hydrolyzing a polyester by contacting the polyester with a solid acid catalyst. Also disclosed are solid acid catalysts that are useful for hydrolyzing a polyester and methods of making the solid acid catalysts. Furthermore, compositions including one or both of a dicarboxylic acid and a diol, and at least one solid acid catalyst are also disclosed.

Abstract: A Doherty power amplifying circuit includes at least two asymmetrical two-branch power devices. Each of the asymmetrical two-branch power devices includes two power amplifiers. In the at least two asymmetrical two-branch power devices, one power amplifier included in each asymmetrical two-branch power device separately forms a peak power amplifier of the Doherty power amplifying circuit, and the other power amplifiers included in all the asymmetrical two-branch power devices jointly form a main power amplifier of the Doherty power amplifying circuit.

Abstract: A Doherty power amplifying circuit includes at least two asymmetrical two-branch power devices. Each of the asymmetrical two-branch power devices includes two power amplifiers. In the at least two asymmetrical two-branch power devices, one power amplifier included in each asymmetrical two-branch power device separately forms a peak power amplifier of the Doherty power amplifying circuit, and the other power amplifiers included in all the asymmetrical two-branch power devices jointly form a main power amplifier of the Doherty power amplifying circuit.

Abstract: One aspect of the present invention provides a method for improving power amplification efficiency of a Doherty power amplifier. The method is applied to a Doherty power amplifier that has two paths of Doherty circuit units connected in parallel. The method includes: when output power of the Doherty power amplifier is within a low out power range, adjusting, by a bias circuit, gate voltages of main power amplifiers and peak power amplifiers in the two paths of Doherty circuit units connected in parallel, in order to cause the peak power amplifiers to be in an off state, and the main power amplifiers in the two paths of Doherty circuit units connected in parallel to be in a main power amplification state and a peak power amplification state respectively.

Abstract: One aspect of the present invention provides a method for improving power amplification efficiency of a Doherty power amplifier. The method is applied to a Doherty power amplifier that has two paths of Doherty circuit units connected in parallel. The method includes: when output power of the Doherty power amplifier is within a low out power range, adjusting, by a bias circuit, gate voltages of main power amplifiers and peak power amplifiers in the two paths of Doherty circuit units connected in parallel, in order to cause the peak power amplifiers to be in an off state, and the main power amplifiers in the two paths of Doherty circuit units connected in parallel to be in a main power amplification state and a peak power amplification state respectively.