Circuit for changing a frequency
View Patent ↗A circuit is provided for multiplying a frequency by a cascade formed of a transadmittance having a transfer characteristic and a transimpedance having a transfer characteristic. The transadmittance includes two terminals for a signal of a first frequency and the transimpedance includes two terminals for a signal of a second frequency. A transfer characteristic of the transimpedance is steeper than a transfer characteristic of the transadmittance, and a modulation region of the transadmittance is larger than a modulation region of the transimpedance.
1. A frequency multiplying circuit for multiplying a first frequency, the circuit comprising: a transadmittance portion having a first transfer characteristic, the transadmittance portion having two input terminals for a signal of said first frequency; and a transimpedance portion having a second transfer characteristic, the transimpedance portion having two output terminals for a signal of a second frequency higher than the first frequency as an output of said multiplying circuit, wherein a transfer characteristic of the transimpedance portion is steeper than a transfer characteristic of the transadmittance portion, and wherein a modulation range of the transadmittance portion is greater than a modulation range of the transimpedance portion.
2. The circuit according to claim 1 , wherein the transadmittance portion has a first symmetrical DC amplifier with a first transistor circuit, a second transistor circuit, and a first constant-current source that is connected to a common emitter terminal of the first transistor circuit and the second transistor circuit.
3. The circuit according to claim 2 , wherein the transimpedance portion has a second symmetrical DC amplifier that has a third transistor circuit and a fourth transistor circuit, wherein the third transistor circuit and the fourth transistor circuit each include at least one transistor, and a resistor connected between the collector and the base of the transistor and said transimpedance portion further including a second constant current source, and wherein the second constant current source is connected to a common emitter terminal of the third and fourth transistor circuits.
4. The circuit according to claim 3 , wherein at least one of the first, second, third or fourth transistor circuits has at least one bipolar transistor.
5. The circuit according to claim 3 , wherein at least one of the first, second, third or fourth transistor circuits has at least one field-effect transistor.
6. The circuit according to claim 3 , wherein first partial currents of the two constant-current sources are collected at a first node that is connected to an operating voltage of the circuit through a first load resistor, second partial currents of the two constant-current sources are collected at a second node that is connected to the operating voltage through a second load resistor, and wherein a first terminal of the transimpedance portion is connected to the first node and a second terminal of the transimpedance portion is connected to a second node.
7. The circuit according to claim 1 , wherein the transadmittance portion and the transimpedance portion are integrated on a chip with a transmit path and a receive path.
8. The circuit according to claim 7 , wherein an electrical connection is formed between the terminals of the transimpedance portion and a transmit path or a receive path.
9. The circuit according to claim 8 , wherein an electrical connection is formed between the terminals of the transadmittance portion and a voltage-controlled oscillator.
10. The circuit according to claim 9 , wherein an output frequency of the voltage-controlled oscillator is two thirds of a transmit frequency, halved for internal signal processing and tripled by the circuit.
11. The circuit according to claim 1 , wherein the transadmittance portion is in series with the transimpedance portion.
12. A frequency multiplying circuit for multiplying a first frequency, the circuit comprising: a transadmittance portion having a voltage-current transfer characteristic, the transadmittance portion having two input terminals for a signal of said first frequency; and a transimpedance portion having a current-voltage transfer characteristic, the transimpedance portion having two output terminals for a signal of a second frequency, which is higher than said first frequency, and which is output from said multiplying circuit, wherein a modulation range of the transadmittance portion is greater than a modulation range of the transimpedance portion.
13. The circuit according to claim 12 , wherein the current-voltage transfer characteristic of the transimpedance portion is steeper than voltage-current transfer characteristic of the transadmittance portion.
14. The circuit according to claim 1 , wherein said transadmittance portion includes two transadmittance output terminals and said transimpedance portion includes two transimpedance input terminals and wherein said two transadmittance output terminals are directly connected to said two transimpedance input terminals.
15. The circuit according to claim 12 wherein said transadmittance portion includes two transadmittance output terminals and said transimpedance portion includes two transimpedance input terminals and wherein said two transadmittance output terminals are directly connected to said two transimpedance input terminals.