Mixer circuit including separated local (LO) terminal and intermediate frequency (IF) terminal

A mixer circuit comprising:

• a first transistor of npn-type and a second transistor of pnp-type which are connected, wherein the emitter of the first transistor is connected to the collector of the second transistor;
• a third transistor of npn-type, whose collector is connected to the emitter of the first transistor;
• a power supply terminal connected to the collector of the first transistor;
• a radio frequency (RF) terminal connected to the collector of the first transistor;
• a local (LO) terminal connected to the base of the first transistor;
• an intermediate frequency (IF) terminal connected to the base of the second transistor;
• and
• a ground terminal connected to the emitter of the third transistor.

A mixer circuit comprising:

• a first transistor of pnp-type and a second transistor of npn-type which are connected, wherein the collector of the first transistor is connected to the collector of the second transistor;
• a third transistor, whose base is connected to the collector of the first transistor;
• a power supply terminal connected to the emitter of the first transistor;
• an intermediate frequency (IF) terminal, connected to the base of the first transistor, for receiving an IF signal;
• a ground terminal connected to the emitter of the second transistor;
• a local (LO) terminal, connected to the base of the second transistor, for receiving an LO signal;
• a radio frequency (RF) terminal, connected to the collector of the third transistor, for receiving said IF signal and said LO signal;
• a first resistor installed between the collector of the third transistor and power supply terminal;
• an emitter terminal connected to an emitter of the third transistor;
• a second resistor and a capacitor installed between the emitter of the third transistor and the ground terminal, wherein the second resistor and the capacitor are connected in parallel;
• a first bias circuit for applying a bias voltage to the first transistor;
• and a second bias circuit for applying a bias voltage to the second transistor.

A mixer circuit comprising:

• a first transistor and a second transistor of different conduction types which are connected, wherein the collector of the first transistor is connected to the collector of the second transistor;
• a third transistor, whose base is connected to the collector of the first transistor;
• a power supply terminal connected to the emitter of the first transistor;
• an intermediate frequency (IF) terminal connected to the base of the first transistor;
• a ground terminal connected to the emitter of the second transistor;
• a local (LO) terminal connected to the base of the second transistor;
• a radio frequency (RF) terminal connected to the collector of the third transistor;
• a first resistor installed between the collector of the third transistor and power supply terminal;
• an emitter terminal connected to an emitter of the third transistor;
• a second resistor and a capacitor installed between the emitter of the third transistor and the ground terminal, wherein the second resistor and the capacitor are connected in parallel;
• a first bias circuit for applying a bias voltage to the first transistor;
• and
• a second bias circuit for applying a bias voltage to the second transistor.