MOSFET Square Law Mixer Simple Mixer (Square Law) VLo 77T 0=4心s+g0-o旷 Vg(t)=ARE cOSωRFt vs (t)=ALo cos@Lot Omar Wing RF IC-Mixers 6 Shanghai Jiao Tong University
Omar Wing RF IC - Mixers Shanghai Jiao Tong University 6 MOSFET Square Law Mixer 1 2 ( ) ( ( ) ( )) 2 d ox BIAS g s W I t C V v t v t L ( ) cos ( ) cos g RF RF s LO LO v t A t v t A t
MOSFET Square Law Mixer dahncord Conversion gain LCoW (S) 2L RF/LO isolation is not good.LO appears as -2IBus ALo cos@Lot in i.A LPF need be inserted between the mixer and the IF amplifier. Omar Wing RF IC-Mixers 7 Shanghai Jiao Tong University
Omar Wing RF IC - Mixers Shanghai Jiao Tong University 7 MOSFET Square Law Mixer ( ) 1 cos( ) 2 d IF ox RF LO RF LO W i C A A t L Conversion gain = (S) 2 ox LO C W A L RF/LO isolation is not good. LO appears as 2 cos in . A LPF need be inserted between the mixer and the IF amplifier. BIAS LO LO d I A t i
Multiplier-Type Mixers Use the MOSFET as a switch.Turn the RF signal on and off by the LO signal at a rate equal to fio.The output will contain frequency components at IF and around all the harmonics offio. Omar Wing RF IC-Mixers 8 Shanghai Jiao Tong University
Omar Wing RF IC - Mixers Shanghai Jiao Tong University 8 Multiplier-Type Mixers Use the MOSFET as a switch. Turn the RF signal on and off by the LO signal at a rate equal to . The output will contain frequency components at IF and around all the harmonics of . LO LO f f
Single Balanced Mixer Single Balaneea Mixer 777m A differential signal Vo/-Vo is applied to M and M2 to steer the source current Ipc+Ig cos @t alternately to I or 1,.The differential output I-1,contains the desired IF and other frequency components. Omar Wing RF IC-Mixers 9 Shanghai Jiao Tong University
Omar Wing RF IC - Mixers Shanghai Jiao Tong University 9 Single Balanced Mixer 1 2 1 2 1 2 A differential signal / is applied to and to steer the source current cos alternately to or . The differential output contains the desired IF and other frequency compon LO LO DC RF RF V V M M I I t I I I I ents