mt_142_fa2011

mt_142_fa2011 - work. We Frst resonate the capacitor. The...

This preview shows pages 1–12. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
University of California, Berkeley Fall 2011 EECS 142 Prof. A. Niknejad Midterm 1. (a) Calculate the Y-parameter for a common gate ampliFer. The in- ductor at the output provides bias and also resonates with C db at frequency f o . Assuming in this technology C db = C gs and C gd =0 , write Y-parameter at frequency f o using g m , C gs , f o and inductor quality factor Q L . Solution: Y 11 = g m + sC gs Y 21 = - g m Y 12 =0 Y 22 = 2 f o C gs Q L + Q - 1 L @ f o (1)

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
(b) Assume your transistor is biased with 1mA current at V =200 mV . The f T at this bias point is 100GHz. Design a matching network to match your input impedance to 50 at 10 GHz . What is the maximum achievable power gain for your ampliFer if inductor Q is 10? Solution: g m = 2 I V gs - V T =10 mS (2) ! C gs = ! ! T g m =1 mS (3) We can use shunt-inductor-series-capacitor to do the matching net-

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: work. We Frst resonate the capacitor. The inductance needed is ! L res = 1 ! C gs = 1 k ( 4 ) The impedance transformation Q match = p 2-1 = 1 therefore the inductance to transform the impedance is ! L match = 1 Q match g m = 100 (5) The series capacitance is calculated as ! C match = g m (1 + Q 2 match ) Q match = 20 mS (6) The total inductance and capacitance needed is L total = 100 // 1 k 2 10 G = 1 . 45 nH (7) C total = 20 mS 2 10 G = 318 fF (8) The Maximum gain is G max = | Y 21 | 2 4 Re ( Y 11 ) Re ( Y 22 ) = ( Q L + Q-1 L ) g m 4 ! C gs = 25 . 25 (9) 2...
View Full Document

This note was uploaded on 01/12/2012 for the course EECS 142 taught by Professor Ee142 during the Fall '04 term at University of California, Berkeley.

Page1 / 12

mt_142_fa2011 - work. We Frst resonate the capacitor. The...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online