Page 313 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits

М1

"'- х "- Filter 1 Fiilter_ 1 Out
-
/ / "
/
/1

Oscillator Signal О Degree
Cosine Signal
Input Si gnal
"-
/
Vrf (t)

М2

"- Х "- Filter 2 Fiilter_ 20ut
-
/ / "
/
l'

Oscillator Signal 90 Degrees
Sine Signal

FIGURE 16-12 А 0- and 90-degreephasing circuit.
The figu1re shows а single signal source VRF( fJ = соs(2ПlRFfJ that is connected to the
input of two mixers Мl and М2. А signal generator соs(2пfosсfJ is connected to the
remaining input terminal of mixeг Мl, and anotheг signal generator siп(2пfosсfJ is

connected to the remaining input of mixer М2.
The outputs of Мl and М2 аге connected to filters Filter_l and Filter_2,
respectively. These filteгs remove the high-frequency signals from the outputs of
the mixeгs. Theгefoгe, the output of mixeг М 1 is

1т

= ; [ 211" 2 (. 21i - 2

Filteг _1 removes the higheг-frequency signal, which гesults in

t -
'lt 1 21Т R J - 271" ' .~ .t ---..'..,..... 271"' ( . . 11" 1
For mixer М2, the output is