Wireless Transmitters

• US 20120063496A1
• Filed: 09/12/2011
• Published: 03/15/2012
• Est. Priority Date: 09/13/2010
• Status: Active Grant

• Current Assignee: IMEC International, Renesas Electronics Corporation
• Original Assignee: IMEC International, Renesas Electronics Corporation
• Inventors: Sano, Tomohiro, Craninckx, Jan, Giannini, Vito, Ingels, Mark
• Granted Patent: US 8,731,099 B2
• Time in Patent Office: Days
• US Class Current: 375/221
• CPC Class Codes: H03F 1/02 Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/045 with means for improving efficiency

Abstract

Transmitter circuits for generating baseband signals having low receiver-band noise are disclosed. In one embodiment, the transmitter circuit comprises an active filtering-and-amplifying component comprising a first input configured to receive a first input signal, and a first output configured to output a first output signal. The transmitter circuit further comprises a passive filtering component comprising a second input connected to the first output and configured to receive the first output signal, a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and a second output configured to output a second output signal having reduced noise as compared to the first output signal. The transmitter still further comprises a number of feedback loops connecting the passive filtering component to the first input.

Claims

1. A transmitter circuit comprising:

an active filtering-and-amplifying component comprising;

a first input configured to receive a first input signal, and

a first output configured to output a first output signal;

a passive filtering component comprising;

a second input connected to the first output and configured to receive the first output signal,

a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and

a second output configured to output a second output signal having reduced noise as compared to the first output signal; and

a number of feedback loops connecting the passive filtering component to the first input.

2. The transmitter circuit of claim 1, wherein each switchable resistance element comprises a switch element and at least one resistance element.

3. The transmitter circuit of claim 1, wherein the plurality of switchable resistance elements are connected in parallel.

4. The transmitter circuit of claim 1, wherein each feedback loop comprises a feedback loop resistance element.

5. The transmitter circuit of claim 4, wherein each feedback loop resistance element comprises a switch element and at least one resistance element.

6. The transmitter circuit of claim 1, wherein the number of switchable resistance elements is equal to the number of feedback loops.

7. The transmitter circuit of claim 6, wherein each feedback loop is connected to a single switchable resistance element.

8. The transmitter circuit of claim 1, further comprising a control component configured to select a pair of resistive switching elements in the passive pole arrangement.

9. The transmitter circuit of claim 8, wherein the control component is further configured to close the switches in the selected pair of resistive switching elements.

10. The transmitter circuit of claim 1, further comprising:

a digital-to-analogue converter; and

a digitally-controlled oscillator, each of which is connected to the first input.

11. The transmitter circuit of claim 1, wherein:

the first input signal comprises a baseband signal, and

the first output signal comprises a first filtered baseband signal.

12. The transmitter circuit of claim 11, wherein:

the second output signal comprises a second filtered baseband signal.

13. The transmitter circuit of claim 12, further comprising a mixer configured to up-convert the second filtered baseband signal to a radio frequency signal.

14. A transceiver comprising:

a number of transmitter circuits, each transmitter circuit comprising;

an active filtering-and-amplifying component comprising;

a first input configured to receive a first input signal, and

a first output configured to output a first output signal;

a passive filtering component comprising;

a second input connected to the first output and configured to receive the first output signal,

a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and

a second output configured to output a second output signal having reduced noise as compared to the first output signal; and

a number of feedback loops connecting the passive filtering component to the first input.

15. The transceiver of claim 14, further comprising a pre-power amplifier connected to each of the transmitter circuits.

16. The transceiver of claim 14, wherein each transmitter circuit further comprises:

a digital-to-analogue converter; and

a digitally-controlled oscillator, each of which is connected to the first input.

17. The transceiver of claim 14, wherein:

the first input signal comprises a baseband signal,

the first output signal comprises a first filtered baseband signal, and

the second output signal comprises a second filtered baseband signal.

18. The transceiver of claim 17, wherein each transmitter circuit further comprises a mixer configured to up-convert the second filtered baseband signal to a radio frequency signal.

19. An integrated circuit comprising:

a transceiver comprising;

a number of transmitter circuits, each transmitter circuit comprising;

an active filtering-and-amplifying component comprising;

a first input configured to receive a first input signal, and

a first output configured to output a first output signal;

a passive filtering component comprising;

a second input connected to the first output and configured to receive the first output signal,

a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and

a second output configured to output a second output signal having reduced noise as compared to the first output signal; and

a number of feedback loops connecting the passive filtering component to the first input.

20. The integrated circuit of claim 19, wherein the transceiver is implemented in complementary metal-oxide-semiconductor technology.