Multi-stage amplifier using tunable transmission lines and frequency response calibration of same
A multi-stage amplifier is provided that uses tunable transmission lines, as well as a calibration method for the multi-stage amplifiers. A multi-stage amplifier, comprises a plurality of tunable amplification stages, wherein each of the tunable amplification stages comprises a tunable resonator based on a transmission line having a tunable element. The tunable elements may vary a capacitance or an inductance to tune a frequency of an applied signal. A calibration method is provided for a multi-stage amplifier having a plurality of transmission lines, an input stage and an output stage. The multi-stage amplifier is calibrated by generating a signal to determine a frequency for a substantially maximum power; generating an error signal by comparing the frequency for the substantially maximum power with a desired frequency; varying a digital control code applied to each of the tunable transmission lines, input stage and output stage until the error signal satisfies predefined criteria.
1. A multi-stage amplifier, comprising:
a plurality of tunable amplification stages, wherein each of said tunable amplification stages comprises a tunable resonator comprising a transmission line having a tunable element, wherein one or more of said tunable elements vary an inductance to tune a frequency.
2. The multi-stage amplifier of claim 1 , wherein one or more of said tunable elements further vary a capacitance to tune a frequency.
3. The multi-stage amplifier of claim 1 , wherein each of said transmission lines are substantially identical and operate at a substantially similar frequency.
4. The multi-stage amplifier of claim 3 , wherein an operating frequency of each of said transmission lines is adjusted to be aligned to a desired required frequency.
5. The multi-stage amplifier of claim 1 , wherein each of said transmission lines operate at a different frequency to provide a broadband design.
6. The multi-stage amplifier of claim 1 , wherein one or more of said transmission lines tune a frequency based on a digital control word that is applied to said transmission lines.
7. The multi-stage amplifier of claim 1 , further comprising an input matching circuit and an output stage matched to a next stage.
8. The multi-stage amplifier of claim 7 , wherein said input matching circuit and said output stage are tunable to obtain a matching at an operating frequency.
9. The multi-stage amplifier of claim 1 , wherein said multi-stage amplifier comprises a low noise amplifier.
10. The multi-stage amplifier of claim 1 , wherein said multi-stage amplifier comprises a power amplifier.
11. The multi-stage amplifier of claim 1 , wherein said multi-stage amplifier operates at a millimeter wave frequency.
12. The multi-stage amplifier of claim 1 , wherein said multi-stage amplifier is integrated on a chip.
13. The multi-stage amplifier of claim 1 , wherein a resonant frequency of said multi-stage amplifier is varied by varying one or more of said inductance and a capacitance of at least one of said transmission lines.
14. The multi-stage amplifier of claim 1 , further comprising an on-chip oscillator for generating a signal having a desired frequency and an on-chip power detector for measuring said signal at an output of said multi-stage amplifier.
15. The multi-stage amplifier of claim 14 , further comprising a state machine for executing a calibration process.
16. The multi-stage amplifier of claim 15 , wherein said calibration process adjusts one or more of a matching of an input stage and an output stage and a gain of said transmission lines having said tunable element.
17. The multi-stage amplifier of claim 1 , wherein at least one of said transmission lines comprises an inductor.
18. A calibration method for a multi-stage amplifier having a plurality of transmission lines, an input stage and an output stage, comprising:
generating a signal to determine a frequency for a substantially maximum power;
generating an error signal by comparing said frequency for said substantially maximum power with a desired frequency;
varying a digital control code applied to said transmission lines until said error signal satisfies a first predefined criteria;
varying a digital control code applied to said input stage until said error signal satisfies a second predefined criteria; and
varying a digital control code applied to said output stage until said error signal satisfies a third predefined criteria.
19. The calibration method of claim 18 , wherein said signal to determine a frequency is generated by an on-chip oscillator.
20. The calibration method of claim 18 , wherein said method is performed by an on-chip state machine.
21. The calibration method of claim 18 , wherein at least one of said transmission lines comprises an inductor.
22. A method for amplifying a signal, comprising:
applying said signal to a multi-stage amplifier, wherein said multi-stage amplifier comprises a plurality of tunable amplification stages, wherein each of said tunable amplification stages comprises a tunable resonator comprising a transmission line having a tunable element; and
varying an inductance of at least one of said tunable elements to vary a frequency of said signal.
23. The method of claim 22 , wherein said multi-stage amplifier further comprises an input matching circuit and an output stage matched to a next stage.
24. The method of claim 22 , wherein said signal has a millimeter wave frequency.