Narrowband LC folded cascode structure
First Claim
Patent Images
1. An apparatus comprising:
- a tank circuit having a resonance frequency, having a first end for connection to a first supply terminal and having a second end, the tank circuit consisting of a narrowband complex impedance having a very low DC resistance and having a high impedance in a range of frequency around said resonance frequency;
an n-channel MOS transistor having a gate for receiving a first input signal, and a drain connected to the second end of the tank circuit;
a p-channel MOS transistor having a drain for connection across a load to a second supply terminal, a source connected to the second end of the tank circuit, and a gate for receiving a second input signal;
wherein the apparatus multiplies the second input signal with the first input signal only within said range of frequency.
11 Assignments
0 Petitions
Accused Products
Abstract
A low voltage cascode frequency conversion mixer circuit is provided. In place of a conventional current source, an LC tank circuit is used. This makes the circuit function as a mixer only over a narrow band of frequencies centred at the resonance frequency of the LC tank circuit. The circuit mixes an input signal with a local oscillator signal. Advantageously, a lower supply voltage may be used because a smaller DC drop exists across the tank circuit than does across conventional current sources. The circuit may also be used as an amplifier by connecting a DC bias voltage in place of the local oscillator.
148 Citations
20 Claims
-
1. An apparatus comprising:
-
a tank circuit having a resonance frequency, having a first end for connection to a first supply terminal and having a second end, the tank circuit consisting of a narrowband complex impedance having a very low DC resistance and having a high impedance in a range of frequency around said resonance frequency; an n-channel MOS transistor having a gate for receiving a first input signal, and a drain connected to the second end of the tank circuit; a p-channel MOS transistor having a drain for connection across a load to a second supply terminal, a source connected to the second end of the tank circuit, and a gate for receiving a second input signal; wherein the apparatus multiplies the second input signal with the first input signal only within said range of frequency. - View Dependent Claims (2)
-
-
3. An apparatus comprising:
-
a tank circuit having a resonance frequency, having a first end for connection to a first supply terminal and having a second end, the tank circuit consisting of a narrowband complex impedance having a very low DC resistance and having a high impedance in a range of frequency around said resonance frequency; a first transistor having first, second and third terminals, with the first terminal for receiving a first input signal, and the second terminal connected to the second end of the tank circuit; a second transistor of complementary type to said first transistor having first, second and third terminals, with the second terminal for connection across a load to a second supply terminal, the third terminal connected to the second end of the tank circuit, and the first terminal for receiving a second input signal; wherein the apparatus multiplies the second input signal with the first input signal only within said range of frequency. - View Dependent Claims (4, 5)
-
-
6. An apparatus comprising:
-
a first tank circuit having a very low DC resistance and having a high impedance in a range of frequency around a resonance frequency, and having a first end for connection to a first supply terminal and having a second end; a second tank circuit having a very low DC resistance and having a high impedance in said range of frequency, and having a first end for connection to the first supply terminal and having a second end; a first transistor having first, second and third terminals, the second terminal connected to the second end of the first tank circuit, the third terminal for connection to a second supply terminal and the first terminal for receiving a first end of a first differential input signal; a second transistor of the same type as said first transistor and having first, second and third terminals, the second terminal connected to the second end of the second tank circuit, the third terminal for connection to the second supply terminal, and the first terminal for receiving a second end of said first differential input signal; a first differential pair of transistors of complementary type to said first and second transistors, and each of the pair having respective first, second and third terminals, the third terminals connected together and to the second end of the first tank circuit, the first terminals for connection to a second differential input signal, one of said second terminals for connection to the second supply terminal through a first load; and a second differential pair of transistors of the same type as said first differential pair of transistors, and each of the pair having respective first, second and third terminals, the third terminals connected together and to the second end of the second tank circuit, the first terminals of the first differential pair cross-connected with the first terminals of the second differential pair, one of said second terminals for connection to the second supply terminal through a second load;
the second terminals of the first differential pair being cross-connected with the second terminals of the second differential pair. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification