Power reconfigurable power amplifier

A method for amplifying an input signal using a power amplifier having a 2N−1 number of input-side reconfigurable quadrature couplers connected in a tree structure, wherein a 2(N−1) number of the input-side reconfigurable quadrature couplers have coupler output terminals, and a root of the tree structure is one of the input-side reconfigurable quadrature couplers having a main input terminal;

• a 2N−1 number of output-side reconfigurable quadrature couplers connected in a tree structure, wherein a 2(N−1) number of output-side reconfigurable quadrature couplers have coupler input terminals, and a root of the tree structure is one of the output-side reconfigurable quadrature couplers having a main output terminal,
• wherein each of the input-side and output-side reconfigurable quadrature couplers comprises:
• a first port transmission line connected to a first port;
• a second port transmission line;
• a second port transformer connected between the second port transmission line and a second port, wherein the second port transformer is configured to have a selectable second port reflection coefficient Γ2;
• a third port transmission line;
• a third port transformer connected between the third transmission line and a third port, wherein the third port transformer is configured to have a selectable third port reflection coefficient Γ3;
• a fourth port transmission line;
• and
• a fourth port transformer connected between the fourth port transmission line and a fourth port, wherein the fourth port transformer is configured to have a selectable fourth port reflection coefficient Γ4;
• the method comprising:
• configuring each input-side and output-side reconfigurable quadrature coupler by selecting reflection coefficients Γ2, Γ3, and Γ4 for the second, third, and fourth port transformers;
• dividing the input signal into constituent amplification paths using the input-side reconfigurable quadrature couplers, wherein each path has an amplifier input terminal connected to corresponding ones of the coupler output terminals and an amplifier output terminal coupled to corresponding ones of the coupler input terminals;
• amplifying the divided input signal using a 2N number of constituent amplifiers, wherein N is a natural counting number greater than or equal to two;
• and
• adjusting gain for differences in loss between a balanced state, a through state, and a coupled state by coupling at least one digital trim step attenuator to a leftmost one of the input-side reconfigurable quadrature couplers.