22.01.2014 Views

download searchable PDF of Circuit Design book - IEEE Global ...

download searchable PDF of Circuit Design book - IEEE Global ...

download searchable PDF of Circuit Design book - IEEE Global ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

248 Linear Amplifier <strong>Design</strong> Tools<br />

Power<br />

P,o<br />

Added power<br />

P L surface<br />

Pin<br />

Plane<br />

-+--+-"'::O'41L.J-1f...:----+-- O',e~1<br />

Figure 7.1t. Output power paraboloid over a Y~2 Smith chart when VI = I.<br />

which clearly occurs when YL = y~2' The nomenclature<br />

Yij =gij +jbij Vi andj (where V means "for all") (7.47)<br />

will be employed consistently. The pertinent load reflection coefficient, according<br />

to (7.17), will be<br />

"'22 y~2-YL. (7.48)<br />

y,,+ Y L<br />

Thus, for V, = I volt, the Linvill and Gibbons (1961) geometric model <strong>of</strong><br />

normalized output power is the paraboloid shown in Figure 7.11. The Pin<br />

plane will be derived in the next section.<br />

7.3.2. Input Admittance Plane. Section 7.2.3 showed how the load plane<br />

could be mapped into the input plane. The development here is similar to that<br />

for the scattering parameters in Section 7.2.2. It begins by writing the input<br />

admittance as a function <strong>of</strong> load admittance, analogous to (3.101) for impedances:<br />

(7.49)

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!