CN106788324B - Loop feedback active resistor - Google Patents
Loop feedback active resistor Download PDFInfo
- Publication number
- CN106788324B CN106788324B CN201611235084.2A CN201611235084A CN106788324B CN 106788324 B CN106788324 B CN 106788324B CN 201611235084 A CN201611235084 A CN 201611235084A CN 106788324 B CN106788324 B CN 106788324B
- Authority
- CN
- China
- Prior art keywords
- passive
- resistor
- capacitor
- active
- loop feedback
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H11/00—Networks using active elements
- H03H11/02—Multiple-port networks
Landscapes
- Amplifiers (AREA)
- Networks Using Active Elements (AREA)
Abstract
A loop feedback active resistor is suitable for the field of radio frequency wireless receivers and comprises: the circuit comprises a first active transistor M1, a second active transistor M2, a first passive resistor R1, a second passive resistor R2, a first passive capacitor C1, a second passive capacitor C2, a first passive inductor L1 and a second passive inductor L2; the transconductance of the currents of the first active transistor M1 and the second active transistor M2 is adjusted by adjusting the currents of the first active transistor M1 and the second active transistor M2, so as to adjust the impedance of the loop feedback active resistor; and/or adjusting the impedance of the loop feedback active resistor by adjusting the impedance of the first passive resistor R1/the first passive capacitor C1/the first passive inductor L1 and the impedance of the second passive resistor R2/the second passive capacitor C2/the second passive inductor/L2 during design.
Description
Technical Field
The invention relates to the field of analog circuits of semiconductor integrated circuits, in particular to a loop feedback active resistor.
Background
The low noise amplifier is an amplifier with very low noise coefficient, generally used as a high frequency or intermediate frequency preamplifier of various radio receivers and an amplifying circuit of a high-sensitivity electronic detection device, is one of important modules in a radio frequency transceiver, and is mainly used for amplifying a signal received from an antenna in a communication system so as to be conveniently processed by a receiver circuit at a later stage.
In the case of amplifying a weak signal, the noise of the amplifier itself may interfere with the signal seriously, and it is desirable to reduce the noise to improve the signal-to-noise ratio of the output. The degree of signal-to-noise ratio degradation caused by the amplifier is typically expressed in terms of a noise figure F. The noise figure F of an ideal amplifier is 1(0 db), which has the physical meaning that the output snr is equal to the input snr.
Since the signal from the antenna is typically very weak, the lna is typically located very close to the antenna to reduce signal loss. It is because the noise amplifier is located in the first stage of the whole receiver in the immediate vicinity of the antenna, and its characteristics directly affect the quality of the received signal of the whole receiver.
To ensure that the signal received by the antenna is correctly recovered at the final stage of the receiver, a good low noise amplifier needs to amplify the signal while producing as little noise and distortion as possible.
With the development of modern mobile communication, the requirement of the low noise amplifier to be suitable for various frequencies and protocols, therefore, higher requirements are put on the inductance of the LNA, especially the requirement of the LNA with variable inductance, to meet the requirements of various frequencies and protocols, so that the whole receiver becomes a broadband receiver. Impedance matching and noise matching of the input terminal are key to achieving high gain and low noise, and the most critical to the influence of impedance matching and noise matching of the input terminal is the inductance of the LNA.
Generally, the low noise amplifier inductance used for input matching is made up of passive devices, where resistance is an important passive component. Generally, the passive resistor of the integrated circuit is fixed after being manufactured by the process, and the impedance of the passive resistor cannot be adjusted. In many applications, however, it would be a great benefit to the circuit design if the resistance of the resistor could be adjusted.
Disclosure of Invention
The invention aims to provide a loop feedback active resistor with adjustable resistance, and in order to realize the aim, the technical scheme of the invention is as follows:
a loop feedback active resistor is suitable for the field of radio frequency wireless receivers; it includes: the circuit comprises a first active transistor M1, a second active transistor M2, a first passive resistor R1, a second passive resistor R2, a first passive capacitor C1, a second passive capacitor C2, a first passive inductor L1 and a second passive inductor L2;
the drains of the first active transistor M1 and the second active transistor M2 are connected as an input end Vinput of the loop feedback active resistor;
the first passive inductor L1 and the first passive resistor R1 are connected in series and then connected in parallel with the first passive capacitor C1, and the second passive inductor L2 and the second passive resistor R2 are connected in series and then connected in parallel with the second passive capacitor C2;
one end of the first passive inductor L1, one end of the second passive inductor L2, one end of the first passive capacitor C1 and one end of the second passive capacitor C2 are connected with the gate of the first active transistor M1;
the other end of the second passive resistor R2 and the other end of the second passive capacitor C2 are connected with the source electrode of the second active transistor M2;
the other end of the first passive resistor R1 and the other end of the first passive capacitor C1 are connected with the source of the first active transistor M1 and the gate of the second active transistor M2 to serve as the input terminal Voutput of the loop feedback active resistor;
wherein, the current transconductance of the current of the first active transistor M1 and the current of the second active transistor M2 is adjusted by adjusting the current of the first active transistor M1 and the current of the second active transistor M2, so as to adjust the impedance of the loop feedback active resistor; and/or
The impedance of the loop feedback active resistor is adjusted by adjusting the impedance of the first passive resistor R1/the first passive capacitor C1/the first passive inductor L1 and the impedance of the second passive resistor R2/the second passive capacitor C2/the second passive inductor/L2 during design.
Preferably, the first passive capacitor C1 includes a parasitic capacitance of the first active transistor M1, which includes a parasitic capacitance of the drain terminal of the first active transistor M1 to ground and a parasitic capacitance of the drain terminal of the first active transistor M1 to the source terminal.
Preferably, the first passive capacitor C1 is not less than the parasitic capacitance of the drain terminal of the first active transistor M1 to ground.
Preferably, the second passive capacitor C2 includes a parasitic capacitor of M2, including a parasitic capacitor of drain terminal to ground of the second active transistor M2 and a parasitic capacitor of drain terminal to source terminal of the second active transistor M2.
Preferably, the first passive resistor R1/the second passive resistor R2 is equal to a times of the first passive capacitor C1/the second passive capacitor C2, wherein a is 0.4-0.9.
Preferably, a is 0.7.
Preferably, the resistance value of the first passive resistor R1 is 300-800 ohms; the first passive capacitor C1 is 100 fF-1 pF; the first passive inductor L1 is 2-5 nH.
Preferably, the first passive resistor R1 has a resistance of 400 ohms.
Preferably, the first passive capacitor C1 is 200 fF.
Preferably, the first passive inductor L1 is 3 nH.
According to the technical scheme, the impedance of the loop feedback active resistor provided by the invention is free from the defect of fixed resistance of the traditional passive device, and has the characteristics of smaller area and easier resistance adjustment compared with other circuits for adjusting the impedance.
Drawings
FIG. 1 is a schematic diagram of the basic principle of the loop feedback resistor of the present invention
FIG. 2 is a schematic circuit diagram of a loop feedback resistor according to an embodiment of the invention
FIG. 3 is a diagram illustrating simulated waveform changes of the impedance of the loop feedback active resistor according to an embodiment of the present invention
Detailed Description
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
Referring to fig. 1, fig. 1 is a schematic diagram illustrating a basic principle of a loop feedback resistor according to the present invention. As shown in the figure, a loop feedback resistor designed to embody the idea of the present invention is between Vinput and Voutput, and it can be known from the feedback theory that impedance Zin ═ Zin1/(1-a × B) of the whole loop feedback resistor, where Zin1 is impedance seen from the forward end of the resistor loop, a × B is loop gain of the resistor loop, a is gain of the amplifier a, and B is gain of the amplifier B.
That is, the impedance Zin of the entire resistor is adjustable by the gain (positive gain) of the amplifier a and the gain (feedback gain) of the amplifier B.
Referring to fig. 2, fig. 2 is a schematic circuit diagram illustrating a loop feedback resistor according to an embodiment of the invention. In the embodiment of the present invention, based on the above design concept, the loop feedback active resistor suitable for the field of radio frequency wireless receivers shown in fig. 2 is connected between Vinput and Voutput, and is composed of the following parts: a first active transistor M1, a second active transistor M2, a first passive resistor R1, a second passive resistor R2, a first passive capacitor C1 and a second passive capacitor C2; a first passive inductor L1 and a second passive inductor L2.
The drains of the first active transistor M1 and the second active transistor M2 are connected to serve as an input end Vinput of the loop feedback active resistor; the first passive inductor L1 is connected with the first passive resistor R1 in series and then connected with the first passive capacitor C1 in parallel, and the second passive inductor L2 is connected with the second passive resistor R2 in series and then connected with the second passive capacitor C2 in parallel; one end of the first passive inductor L1, one end of the second passive inductor L2, one end of the first passive capacitor C1 and one end of the second passive capacitor C2 are connected with the gate of the first active transistor M1; the other end of the second passive resistor R2 and the other end of the second passive capacitor C2 are connected with the source electrode of the second active transistor M2; the other end of the first passive resistor R1 and the other end of the first passive capacitor C1 are connected to the source of the first active transistor M1 and the gate of the second active transistor M2 as the input terminal Voutput of the loop feedback active resistor.
As shown in fig. 2, it can be analyzed through a small-signal equivalent circuit model, and the loop feedback active resistance has a loop gain G:
where gm1 is the transconductance of the first active transistor M1, gm2 is the transconductance of the second active transistor M2, ro2 is the source-drain resistance of the second active transistor M2, and Rs is the standard impedance (50 ohms).
Z1 is the load resistance as seen from node a in the figure, Z1 ═ (R1+ j ω L1) | |1/j ω C1
Z2 is the load resistance as seen from node b in the figure, Z2 ═ (R2+ j ω L2) |1/j ω C2
Therefore, the impedance of the loop feedback active resistor is:
as can be seen from the above-mentioned formula,
(1) the current transconductance of the current of the first active transistor M1 and the current of the second active transistor M2 are adjusted by adjusting the current of the first active transistor M1 and the current of the second active transistor M2, and the impedance of the loop feedback active resistor is further adjusted; and/or
(2) The impedance of the loop feedback active resistor is adjusted by adjusting the impedance of the first passive resistor R1/the first passive capacitor C1/the first passive inductor L1 and the impedance of the second passive resistor R2/the second passive capacitor C2/the second passive inductor/L2 during design.
It is to be noted that the first passive capacitor C1 in fig. 2, strictly speaking, the first passive capacitor C1 itself, further includes a parasitic capacitance of the first active transistor M1, that is, the first passive capacitor C1 includes a parasitic capacitance of the first active transistor M1, the parasitic capacitance includes a drain-to-ground parasitic capacitance of the first active transistor M1 and a drain-to-ground parasitic capacitance of the first active transistor M1, and the first passive capacitor C1 is not smaller than the drain-to-ground parasitic capacitance of the first active transistor M1; likewise, the second passive capacitor C2 includes not only the second passive capacitor C2 itself, but also the parasitic capacitance of the second active transistor M2, i.e., the parasitic capacitance of the drain terminal to ground of the second active transistor M2 and the parasitic capacitance of the drain terminal to source terminal of the second active transistor M2.
Design experience shows that in the design of the loop feedback active resistor, the following key points exist:
①, the first passive resistor R1/the second passive resistor R2 can be equal to a times of the first passive capacitor C1/the second passive capacitor C2, wherein a is 0.4-0.9.
②, the resistance of the first passive resistor R1 can be 300-800 ohms to 300-800 ohms in the preferred embodiment of the invention, the resistance of the first passive resistor R1 is 400 ohms;
③, the first passive capacitor C1 may be 100 fF-1 pF, in the preferred embodiment of the present invention, the first passive capacitor C1 is 200fF, please note that the first passive capacitor C1 cannot be smaller than the parasitic capacitance of the drain terminal of the first active transistor M1;
④, the first passive inductor L1 may be 2-5 nH, and in the preferred embodiment of the present invention, the first passive inductor L1 is 3 nH.
The beneficial effect of the loop feedback active resistor of the present invention is illustrated by a preferred embodiment of the present invention. Referring to fig. 3, fig. 3 is a graph illustrating simulated waveform variations of the impedance of the loop feedback active resistor according to an embodiment of the present invention, wherein the abscissa of fig. 3 is frequency (frequency) and the ordinate is input impedance (input impedance).
As can be seen from fig. 3, by adjusting the resistance of the second passive resistor R2, the impedance of the loop feedback active resistor can be effectively adjusted. In a radio frequency system, the impedance is usually required to meet a standard impedance of 50 ohms, that is, compared with the second passive resistor R2 being equal to 0, by increasing the resistance value of the second passive resistor R2, the frequency range of the resistor meeting the standard impedance of 50 ohms can be effectively widened, so that the resistor impedance can meet the application field of a wider frequency band.
In summary, the loop feedback active resistor provided by the invention overcomes the defect of fixed resistance of the traditional passive device, and has the characteristics of smaller area and easier resistance adjustment compared with other circuits for adjusting impedance.
The above description is only for the preferred embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, so that all the equivalent structural changes made by using the contents of the description and the drawings of the present invention should be included in the scope of the present invention.
Claims (10)
1. A loop feedback active resistor is suitable for the field of radio frequency wireless receivers; it is characterized by comprising: the circuit comprises a first active transistor M1, a second active transistor M2, a first passive resistor R1, a second passive resistor R2, a first passive capacitor C1, a second passive capacitor C2, a first passive inductor L1 and a second passive inductor L2;
the drains of the first active transistor M1 and the second active transistor M2 are connected as an input end Vinput of the loop feedback active resistor;
the first passive inductor L1 and the first passive resistor R1 are connected in series and then connected in parallel with the first passive capacitor C1, and the second passive inductor L2 and the second passive resistor R2 are connected in series and then connected in parallel with the second passive capacitor C2;
one end of the first passive inductor L1, one end of the second passive inductor L2, one end of the first passive capacitor C1 and one end of the second passive capacitor C2 are connected with the gate of the first active transistor M1;
the other end of the second passive resistor R2 and the other end of the second passive capacitor C2 are connected with the source electrode of the second active transistor M2;
the other end of the first passive resistor R1 and the other end of the first passive capacitor C1 are connected with the source of the first active transistor M1 and the gate of the second active transistor M2 to serve as the input terminal Voutput of the loop feedback active resistor;
wherein, the current transconductance of the current of the first active transistor M1 and the current of the second active transistor M2 is adjusted by adjusting the current of the first active transistor M1 and the current of the second active transistor M2, so as to adjust the impedance of the loop feedback active resistor; and/or
The impedance of the loop feedback active resistor is adjusted by adjusting the impedance of any first passive resistor R1/first passive capacitor C1/first passive inductor L1 and any second passive resistor R2/second passive capacitor C2/second passive inductor L2 during design.
2. The loop feedback active resistor of claim 1, wherein the first passive capacitor C1 comprises a parasitic capacitor of the first active transistor M1, the parasitic capacitor comprises a drain-to-ground parasitic capacitor of the first active transistor M1 and a drain-to-source parasitic capacitor of the first active transistor M1.
3. The loop feedback active resistor of claim 2, wherein the first passive capacitor C1 is not less than a parasitic capacitance of the drain terminal of the first active transistor M1 to ground.
4. The loop feedback active resistor of claim 1, wherein the second passive capacitor C2 comprises a parasitic capacitor of M2, a parasitic capacitor of drain terminal to ground of the second active transistor M2, and a parasitic capacitor of drain terminal to source terminal of the second active transistor M2.
5. The loop feedback active resistor of claim 1, wherein the first passive resistor R1/the second passive resistor R2 is equal to a times the first passive capacitor C1/the second passive capacitor C2, wherein a is 0.4-0.9.
6. The loop-feedback active resistor of claim 5, wherein a is 0.7.
7. The loop feedback active resistor of claim 1, wherein the first passive resistor R1 has a resistance value of 300-800 ohms; the first passive capacitor C1 is 100 fF-1 pF; the first passive inductor L1 is 2-5 nH.
8. The loop feedback active resistor of claim 7, wherein the first passive resistor R1 has a resistance of 400 ohms.
9. The loop feedback active resistor of claim 7, wherein the first passive capacitor C1 is 200 fF.
10. The loop feedback active resistor of claim 7, wherein the first passive inductor L1 is 3 nH.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611235084.2A CN106788324B (en) | 2016-12-28 | 2016-12-28 | Loop feedback active resistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611235084.2A CN106788324B (en) | 2016-12-28 | 2016-12-28 | Loop feedback active resistor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106788324A CN106788324A (en) | 2017-05-31 |
| CN106788324B true CN106788324B (en) | 2020-05-15 |
Family
ID=58924535
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611235084.2A Active CN106788324B (en) | 2016-12-28 | 2016-12-28 | Loop feedback active resistor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106788324B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110456853A (en) * | 2018-05-07 | 2019-11-15 | 深迪半导体(上海)有限公司 | The reading circuit of capacitance type sensor |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102324896A (en) * | 2011-07-11 | 2012-01-18 | 复旦大学 | Low-noise broadband amplifier with linearity compensation |
| US9590302B2 (en) * | 2013-07-10 | 2017-03-07 | U&U Engineering Inc. | Active antenna module |
-
2016
- 2016-12-28 CN CN201611235084.2A patent/CN106788324B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102324896A (en) * | 2011-07-11 | 2012-01-18 | 复旦大学 | Low-noise broadband amplifier with linearity compensation |
| US9590302B2 (en) * | 2013-07-10 | 2017-03-07 | U&U Engineering Inc. | Active antenna module |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106788324A (en) | 2017-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7834698B2 (en) | Amplifier with improved linearization | |
| CN103117711B (en) | Monolithic integrated radio frequency high-gain low-noise amplifier | |
| CN110729974A (en) | Ultra-wideband high-gain low-noise amplifier | |
| US9312818B2 (en) | Low-noise amplifier | |
| CN107769736B (en) | Self-biased broadband low noise amplifier | |
| US9184716B2 (en) | Low noise amplifier and receiver | |
| CN107592081A (en) | A kind of ultra wide band monolithic microwave integrated low-noise amplifier | |
| CN102983817B (en) | High-gain wideband low-noise amplifier | |
| CN110896300A (en) | Broadband low-noise amplifier | |
| CN111740705A (en) | Low-noise amplifier for eliminating nonlinearity | |
| CN116131770A (en) | High-integration-level high-linearity low-noise amplifier | |
| CN106788324B (en) | Loop feedback active resistor | |
| CN111478671B (en) | Novel low-noise amplifier applied to Sub-GHz frequency band | |
| KR101590605B1 (en) | Linear power amplifier for wireless transmitter | |
| CN103475314B (en) | low-noise amplifier | |
| KR101123211B1 (en) | Low noise amplifier and radio receiver | |
| CN103973233A (en) | Low-noise amplifier based on differential structure active inductor | |
| Zhou et al. | Ultra-wideband low noise amplifier employing noise cancelling and simultaneous input and noise matching technique | |
| Wang et al. | A CMOS 2-11 GHz Continuous Variable Gain UWB LNA | |
| CN106803746B (en) | Low-noise amplifier | |
| CN112865712B (en) | Low noise amplifier | |
| CN108574463A (en) | Low-noise amplifier and RF front-end circuit | |
| CN109936337B (en) | Radio frequency amplifying circuit and integrated circuit with same | |
| CN104506146B (en) | Wideband low noise amplifier based on on-chip inductor | |
| CN104883136B (en) | A kind of single-ended grid CMOS low-noise amplifiers altogether of negative resistance formula |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |