.PS cct_init # Usual defs... qrt=dimen_/4; hlf=dimen_/2; dim=dimen_; Org:Here # Multiplier carrier=6; line -> from Org+(0,-1.25*dim) to Org+(0,1.25*dim) line -> from Org to Org+(3.5*dim, 0); "t" below_ # Decaying sinusoid. move to Org maxaxis = 2*dim*(twopi_) onedegree = twopi_/360; for theta = 0 to 3*pi_ by onedegree do { line to Org+(theta/maxaxis, 1.5*dim*sin(theta)*exp(-0.1*theta)) } Org:Org + (4.5*dim,0) line -> from Org-(0,1.25*dim) to Org+(0,1.25*dim) line -> from Org to Org+(2.5*dim, 0); "t" below_ # Carrier move to Org maxaxis = 2*dim*(carrier*twopi_) onedegree=twopi_/360; for theta = 0 to carrier*twopi_ by onedegree do { line to Org+(theta/maxaxis, dim*sin(theta)) } Org:Org + (3.5*dim,0) line -> from Org-(0,1.25*dim) to Org+(0,1.25*dim) line -> from Org to Org+(3.5*dim, 0); "t" below_ # AM (Try this with a mouse...) move to Org maxaxis = 2*dim*(carrier*twopi_) onedegree=twopi_/360; for theta = 0 to carrier*3*pi_ by onedegree do { line to Org+(theta/maxaxis, \ 1.5*dim*sin(theta)*sin(theta/carrier)*exp(-0.1*theta/carrier)) } # +ve envelope move to Org maxaxis = 2*dim*twopi_ onedegree=20*pi_/360; for theta = 0 to 3*pi_ by onedegree do { dot(at Org+(theta/maxaxis, 1.5*dim*sin(theta)*exp(-0.1*theta)),0.001) } # -ve envelope move to Org maxaxis = 2*dim*twopi_ onedegree=20*pi_/360; for theta = 0 to 3*pi_ by onedegree do { dot(at Org+(theta/maxaxis, -1.5*dim*sin(theta)*exp(-0.1*theta)),0.001) } "{\Huge $\times$}" at (4*dim,-0.1*dim) "{\Huge $=$}" at (7.5*dim,-0.1*dim) "Signal" at (1.5*dim,1.5*dim) "Carrier" at (5.5*dim, 1.5*dim) "Modulation" at 9.5*dim, 1.5*dim # Frequency Domain (Convolved) move to (1.75*dim, -3*dim) Org: Here line -> from Org+(0,-1.25*dim) to Org+(0,1.25*dim) line -> from Org+(-1.5*dim,0) to Org+(1.5*dim, 0); "f" below_ move to Org+(0, dim) {line left_ 0.75*dim down_ dim} {line right_ 0.75*dim down_ dim ; right_; "10 kHz" below_} Org:Org + (4*dim, 0) move to Org line -> from Org-(0,1.25*dim) to Org+(0,1.25*dim) line -> from Org-(1.3*dim,0) to Org+(1.3*dim, 0); "f" below_ move to Org line <- from Org+(0.65*dim,dim) to Org+(0.65*dim,0) ; "702 kHz" below_ line <- from Org-(0.65*dim,-dim) to Org-(0.65*dim,0) ; "-702 kHz" below_ Org:Org + (4*dim, 0); move to Org line -> from Org-(0,1.25*dim) to Org+(0,1.25*dim) line -> from Org-(1.8*dim,0) to Org+(1.8*dim, 0); "f" below_ move to Org line <- from Org+(dim,1.25*dim) to Org+(dim,0) ; "702 kHz" below_ line <- from Org-(dim,-1.25*dim) to Org-(dim,0) ; "-702 kHz" below_ move to Org+(dim, dim) {line left_ 0.25*dim down_ dim} {line right_ 0.25*dim down_ dim ; right_} {line <-> from Here-(0.25*dim, 1.5*dim) to \ Here + (0.25*dim, -1.5*dim)} "20 kHz" at Here - (0, 1.75*dim) move to Org+(-dim, dim) {line left_ 0.25*dim down_ dim} {line right_ 0.25*dim down_ dim ; right_} "{\Huge $\otimes$}" at (4*dim, -3.1*dim) "{\Huge $=$}" at 7.5*dim, -3.1*dim "\tiny AMModulation" at (9*dim,-4.5*dim) .PE