. The Bell System technical journal . Fig. 7.—Performance of 3/2—power-law rectifier as an envelope detector with low-imped-ance signal generator. To express the output in terms of a source voltage f o in series with animpedance equal to the real constant value ro at t,he signal frequency andzero at all other frequencies, we write ra ai 3C,P3/2(1 _ X)2 :^7|—/^(^f,-I;3r^-j () THE BIASED IDEAL RECTIFIER 153 or Po = (i+|^)p. () where E = 3i?a(l - X)2/i 4\/2= ?^ / ^ 1 -*X\ P 11> ij ^ 2 / () V2P[2(1 - ife + )fe)£ - (2 - yfe)(l - k)K]. 15 20 25 Pq in volts Fig. 8.—Performance
. The Bell System technical journal . Fig. 7.—Performance of 3/2—power-law rectifier as an envelope detector with low-imped-ance signal generator. To express the output in terms of a source voltage f o in series with animpedance equal to the real constant value ro at t,he signal frequency andzero at all other frequencies, we write ra ai 3C,P3/2(1 _ X)2 :^7|—/^(^f,-I;3r^-j () THE BIASED IDEAL RECTIFIER 153 or Po = (i+|^)p. () where E = 3i?a(l - X)2/i 4\/2= ?^ / ^ 1 -*X\ P 11> ij ^ 2 / () V2P[2(1 - ife + )fe)£ - (2 - yfe)(l - k)K]. 15 20 25 Pq in volts Fig. 8.—Performance of 3/2—power-law rectifier as an envelope detector with impedanceof signal generator low except in signal band. By combining the curves of Fig. 7 giving V in terms of P with the aboveequations giving the relation between P and Pq, we obtain the curves ofFigs. 8, 9, 10, giving F as a function of Pq. The curves approach linearityas Ra is made large. On the assumption that the curves are actually linear,we define the conversion loss D of the detector in db in terms of the ratioof maximum power available from the source to the power delivered to theload: D = 10 log! Po/8ro vyR = 10 logi m R^ Sro () Curves of D vs r^/R are given in Figs. 11 and 12. The optimum relationbetween r^ and R when the forward resistance of the rectifier vanishes haslong been known to be r^/R. — .5. The curves show a minimum in this 154 BELL SYSTEM TECHNICAL JOURNAL region when Ra is large. In the limit as Ra approaches infinity, we mayshow that the relation betwee
Size: 1858px × 1345px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
