Integrated tunable high efficiency power amplifier

A tunable high efficiency power amplifier, comprising:

• an active device connected to receive an RF input signal at a control input and having a current circuit which is switched between conductive and non-conductive states in accordance with said RF input signal,
• a network of reactive devices connected to said current circuit, said active device and said network forming a power amplifier arranged to amplify said RF input signal over a range of input signal frequencies determined by the values of said reactive devices, said reactive devices comprising:
• at least one inductance, and
• at least one capacitance,
• at least one of said at least one capacitances being a tunable capacitor comprising at least one micro-electromechanical (MEM) device having first and second terminals, said tunable capacitor arranged to continuously vary the capacitance value between said first and second terminals in accordance with the value of a control signal such that said range of input signal frequencies over which said amplifier is operational is varied in accordance with said control signal, thereby enabling said amplifier to operate efficiently over a wider range of input frequencies, and
• a control circuit arranged to provide said control signal to said tunable capacitor and thereby establish its capacitance, said control circuit including a digital-to-analog (D/A) converter which produces said control signal in response to a digital command signal.

A tunable class E power amplifier, comprising:

• an active device connected to receive an RF input signal at a control input and having a current circuit which is switched between conductive and non-conductive states in accordance with said RF input signal,
• a bias inductor connected to said current circuit,
• a network of reactive devices connected to said current circuit, said active device, said bias inductor and said network of reactive devices forming a class E power amplifier arranged to amplify said Rf input signal over a range of input signal frequencies determined by the values of said reactive devices, said reactive devices comprising:
• a shunt capacitor,
• a series inductor, and
• a series capacitor,
• at least two of said shunt capacitor, said series inductor and said series capacitor being tunable reactive devices, each of which comprises at least one micro-electromechanical (MEM) device that operates in response to a respective control signal and that varies its respective tunable reactive device's reactance value in accordance with said control signal such that said range of input signal frequencies over which said amplifier is operational is varied in accordance with said control signals, thereby enabling said amplifier to operate efficiently over a wider range of input frequencies, and
• a control circuit arranged to provide said control signals to each of said at least two MEM devices and thereby establish the reactance value of each MEM device's respective tunable reactive device.

A tunable class C power amplifier, comprising:

• an active device connected to receive an RF input signal at a control input and having a current circuit which is switched between conductive and non-conductive states in accordance with said RF input signal,
• a bias inductor connected to said control input of said active device,
• a blocking capacitor connected to said current circuit,
• a network of reactive devices connected to said current circuit, said active device, said bias inductor, said blocking capacitor and said network of reactive devices forming a class C power amplifier arranged to amplify said RF input signal over a range of input signal frequencies determined by the values of said reactive devices, said reactive devices arranged in a parallel tuned circuit which is connected to said current circuit and comprising:
• a capacitor, and
• an inductor,
• at least one of said capacitor and said inductor connected in said parallel tuned circuit being a tunable reactive device comprising at least one micro-electromechanical (MEM) device that operates in response to a respective control signal and that varies its respective tunable reactive device's reactance value in accordance with said control signal such that said range of input signal frequencies over which said amplifier is operational is varied in accordance with said control signal, thereby enabling said amplifier to operate efficiently over a wider range of input frequencies, and
• a control circuit arranged to provide said control signals to each of said at least one MEM device and thereby establish the reactance value of each MEM device's respective tunable reactive device.

A tunable class C-E power amplifier, comprising:

• an active device connected to receive an RF input signal at a control input and having a current circuit which is switched between conductive and non-conductive states in accordance with said RF input signal,
• a bias inductor connected to said current circuit,
• a network of reactive devices connected to said current circuit, said active device, said bias inductor and said network of reactive devices forming a class C-E power amplifier arranged to amplify said Rf input signal over a range of input signal frequencies determined by the values of said reactive devices, said reactive devices comprising:
• a shunt capacitor,
• a series inductor, and
• a series capacitor,
• at least two of said shunt capacitor, said series inductor and said series capacitor being tunable reactive devices, each of which comprises at least one micro-electromechanical (MEM) device that operates in response to a respective control signal and that varies its respective tunable reactive device's reactance value in accordance with said control signal such that said range of input signal frequencies over which said amplifier is operational is varied in accordance with said control signals, thereby enabling said amplifier to operate efficiently over a wider range of input frequencies, and
• a control circuit arranged to provide said control signals to each of said at least one MEM devices and thereby establish the reactance value of each MEM device's respective tunable reactive device.

A tunable class F power amplifier, comprising:

• an active device connected to receive an RF input signal at a control input and having a current circuit which is switched between conductive and non-conductive states in accordance with said RF input signal,
• a bias inductor connected to said current circuit,
• a capacitor connected in series with said current circuit,
• a network of reactive devices connected to said current circuit, said active device, said bias inductor, said capacitor and said network of reactive devices forming a class F power amplifier arranged to amplify said RF input signal over a range of input signal frequencies determined by the values of said reactive devices and to produce said amplified RF input signal at an output, said reactive devices arranged in one or more parallel tuned circuits connected to said output, each of said parallel tuned circuits comprising:
• a capacitor, and
• an inductor,
• said capacitor and said inductor connected in said parallel tuned circuit being tunable reactive devices, each of which comprises at least one micro-electromechanical (MEM) device that operates in response to a respective control signal and that varies its respective tunable reactive device's reactance value in accordance with said control signal such that said range of input signal frequencies over which said amplifier is operational is.