The following file determines the dc operating point of a simple differential pair. In addition, the ac small-signal response is computed over the frequency range 1Hz to 100MHz.
Simple differential pair.
vcc 7 0 12
vee 8 0 -12
vin 1 0 ac 1
rs1 1 2 1k
rs2 6 0 1k
q1 3 2 4 mod1
q2 5 6 4 mod1
rc1 7 3 10k
rc2 7 5 10k
re 4 8 10k
.model mod1 npn bf=50 vaf=50 is=1.E-12 rb=100 cjc=.5pf tf=.6ns
.ac dec 10 1 100meg
.end