Oscillator for outputting different oscillation frequencies
View Patent ↗An oscillator includes: oscillation units ( 11 through 1 n) outputting oscillation signals of different frequencies; a transmission line ( 15 ) to which outputs of the oscillation units ( 11, 12 ) are connected, the transmission line having a characteristic impedance corresponding to an output impedance of an output terminal (Tout); and a low-pass filter 818 ) connected between the transmission line ( 15 ) and the output terminal.
1. An oscillator comprising:
oscillation units outputting oscillation signals of different frequencies;
a transmission line to which outputs of the oscillation units are connected, the transmission line having a characteristic impedance corresponding to an output impedance of an output terminal; and
a low-pass filter connected between the transmission line and the output terminal,
wherein the transmission line is grounded via a capacitor and a resistor corresponding to the output impedance.
2. The oscillator as claimed in claim 1 , wherein the transmission line is formed by a strip line.
3. The oscillator as claimed in claim 1 , wherein the low-pass filter is a n-type filter composed of an inductor and two capacitors.
4. The oscillator as claimed in claim 1 , wherein:
the oscillation units respectively include transistors; and
the outputs of the oscillation units are formed by collectors of the transistors.
5. The oscillator as claimed in claim 4 , wherein resonance circuits are connected to bases of the transistors.
6. The oscillator as claimed in claim 4 , wherein:
two capacitors are connected in series between a base of each of the transistors and ground; and
a node between the two capacitors is connected to the emitter of a corresponding one of the transistors.
7. The oscillator as claimed in claim 4 , further comprising a feedback circuit connected to emitters of the transistors and fed back to bases thereof.