Linearized darlington amplifier
View Patent ↗An apparatus comprising a Darlington transistor pair and a common-base transistor. The Darlington transistor pair may be configured to generate an output signal in response to an input signal. The common-base transistor may (i) be coupled between an output transistor of the Darlington transistor pair and the output signal and (ii) have a base configured to receive a frequency dependent reference voltage.
1. An apparatus comprising:
a Darlington transistor pair configured to generate an output signal in response to an input signal; and
a common-base transistor (i) coupled between an output transistor of said Darlington transistor pair and said output signal and (ii) having a base configured to receive a frequency dependent reference voltage.
2. The apparatus of claim 1 , wherein said frequency dependent reference voltage is configured to optimize performance of said apparatus.
3. The apparatus according to claim 1 , wherein said frequency dependent reference voltage is generated by a reference circuit.
4. The apparatus according to claim 3 , wherein said reference circuit includes an emitter follower and an inductive element.
5. The apparatus according to claim 4 , wherein said reference circuit further includes a series RLC tank configured to optimize linearity, gain and stability performance.
6. The apparatus according to claim 3 , wherein said reference circuit is electronically tunable to control linearity of said apparatus.
7. The apparatus according to claim 1 , wherein said common-base transistor improves broadband linearity (IP3) of said apparatus.
8. The apparatus according to claim 1 , wherein said common-base transistor is configured in cascode with said output transistor.
9. The apparatus according to claim 1 , wherein said Darlington transistor pair further comprises an input transistor.
10. The apparatus according to claim 1 , wherein said common-base transistor is configured to adjust the phase of said output signal.
11. The apparatus according to claim 3 , wherein said reference circuit comprises a DC voltage reference configured to provide a DC bias to the base of said common-base transistor.
12. The apparatus according to claim 11 , wherein said reference circuit is further configured to provide a frequency dependent AC impedance to the base of said common-base transistor.
13. An apparatus comprising:
means for configuring a Darlington transistor pair to generate an output signal in response to an input signal; and
means for configuring a common-base transistor (i) coupled between an output transistor of said Darlington transistor pair and said output signal and (ii) having a base configured to receive a frequency dependent linearity reference voltage.
14. A method for implementing a linearized Darlington amplifier comprising the steps of:
(A) configuring a Darlington transistor pair to generate an output signal in response to an input signal; and
(B) coupling a common-base transistor between an output transistor of said Darlington transistor pair and said output signal, wherein a base of said common-base transistor is configured to receive a frequency dependent reference voltage.
15. The method of claim 14 , wherein said frequency dependent reference voltage is configured to optimize performance of said Darlington amplifier.
16. The method according to claim 14 , further comprising the step of:
generating said frequency dependent reference voltage with a reference circuit.
17. The method according to claim 14 , wherein said frequency dependent reference voltage is electronically tunable to control linearity of said Darlington amplifier.
18. The method according to claim 14 , wherein step (B) improves broadband linearity (IP3) of said Darlington amplifier.
19. The method according to claim 14 , wherein said common-base transistor is configured to adjust the phase of said output signal.
20. The method according to claim 14 , wherein step (B) is further configured to provide a frequency dependent AC impedance to the base of said common-base transistor.