CN205566227U - Multiplexing type radio frequency amplifier of electric current - Google Patents

Abstract

The utility model discloses a multiplexing type radio frequency amplifier of electric current, it includes input matching circuit and inverter circuit, and wherein, input matching circuit includes that NMOS pipe NM1, the 3rd NMOS pipe NM3, fourth NMOS manage NM4, inductance L2 and electric capacity C1, and inverter circuit includes the 2nd NMOS pipe NM2 and PMOS pipe PM1, radio frequency input RFIN concatenate behind the electric capacity C1 with NMOS pipe NM1's source electrode, the 3rd NMOS pipe NM3's source electrode and fourth NMOS pipe NM4's source connection, inductance L2's a termination in NMOS pipe NM1's source electrode, inductance L2's other end ground connection, the 2nd NMOS pipe NM2's source electrode and NMOS pipe NM1's drain electrode, the 3rd NMOS pipe NM3's drain electrode and fourth NMOS pipe NM4's drain electrode are connected.

Description

A kind of current multiplexing type radio frequency amplifier

Technical field

This utility model belongs to the manufacture field of the radio frequency amplifier in RFID reader, is specifically related to a kind of electricity The radio frequency amplifier of stream composite.

Background technology

Recent years along with the development of 900MHz and 2.4GHz band RFID technology, to RFID reader Performance is had higher requirement, and more pays close attention to the performance of chip, and the index such as power consumption and cost.And Radio-frequency front-end amplifier is as the important module in RFID reader, and its characteristic also determine whole receiver module Performance, such as noise and sensitivity etc..Radio frequency amplifier requires that having certain gain noise simultaneously to the greatest extent may be used Can low, thus suppress the noise of the subsequent module such as frequency mixer, thus finally improve whole RFID reader Sensitivity.

The major parameter of performance describing radio frequency amplifier has: noise coefficient, voltage gain, inputs and exports Loss, reverse isolation degree and the linearity etc..Owing to these parameters are restrictions interrelated, mutual, because of Which kind of compromise proposal this uses become the Major Difficulties of design to the overall performance improving amplifier.

Traditional radio frequency amplifier sees Fig. 1, is generally divided into two-stage, and the first order is cathode-input amplifier, has relatively Good input coupling, the second level uses phase inverter, can relatively improve the gain of entirety and reduce certain noise Coefficient, but the power consumption of traditional radio frequency amplifier is relatively large, and overall performance is the highest.

Utility model content

Therefore, in order to solve above-mentioned technical problem, it is thus achieved that more high-gain, more low-noise factor, power consumption is relative The radio frequency amplifier that less, overall performance is high, the utility model proposes a kind of current multiplexing type radio frequency amplifier, Its novelty the second level is moved at the power supply of the first order, add some components and parts, constitute this practicality new The radio frequency amplifier of type, it is achieved that current multiplexing, has reached the target of low-power consumption.

In order to solve above-mentioned technical problem, this utility model be employed technical scheme comprise that, a kind of current multiplexing Type radio frequency amplifier, including input matching circuit and inverter circuit；Wherein, input matching circuit includes One NMOS tube NM1, the 3rd NMOS tube NM3, the 4th NMOS tube NM4, inductance L2 and electricity Holding C1, inverter circuit includes the second NMOS tube NM2 and PMOS PM1；Wherein, a NMOS The grid of pipe NM1 as offset side VB1, the grid of the 3rd NMOS tube NM3 as offset side VB2, The grid of the 4th NMOS tube NM4 is as offset side VB3；Electric capacity C1 is input capacitance, and radio frequency is defeated Enter to hold source electrode, the 3rd NMOS tube NM3 with the first NMOS tube NM1 after RFIN serial capacitance C1 Source electrode and the 4th NMOS tube NM4 source electrode connect, inductance L2 is source negative feedback inductor, electricity One end of sense L2 is connected to the source electrode of the first NMOS tube NM1, the other end ground connection of inductance L2；2nd NMOS The source electrode of pipe NM2 and the drain electrode of the first NMOS tube NM1, the drain electrode of the 3rd NMOS tube NM3, with And the 4th NMOS tube NM4 drain electrode connect, the grid of the second NMOS tube NM2 is connected to PMOS The grid of pipe PM1, the drain electrode of the second NMOS tube NM2 is connected to the drain electrode of PMOS PM1, PMOS The source electrode of pipe PM1 is connected to supply voltage RFVDD.

Wherein, NMOS tube NM1, NM2, NM3, inductance L2 and electric capacity C1 together constitute first The input matching circuit of level amplifier, radiofrequency signal inputs from the source electrode of NM1, for common grid structure for amplifying, C1 For input capacitance, allowing radiofrequency signal smoothly enter NMOS tube, inductance L2 is source negative feedback electricity Sense, affects the stability of system, input coupling and the noise coefficient of circuit.If VB2 and VB3 adds same The bias voltage of sample, then NM3 pipe and NM4 also access, and NM1 pipe is in parallel, provide together input across Lead, so can increase the gain of whole amplifier, also make overall gain adjustable.

As a preferred scheme, inverter circuit also includes for leading to the direct current inductance L1 every exchange, electricity Sense L1 is serially connected between input matching circuit and inverter circuit, concrete, and one end of inductance L1 connects the The source electrode of two NMOS tube NM2, the other end of inductance L1 connects the drain electrode of the first NMOS tube NM1.

As a preferred scheme, inverter circuit also includes the gain flattening electricity for making high frequency treatment Sense L3 and electric capacity C4, inductance L3 and electric capacity C4 are connected in series, and are connected to the second NMOS tube NM2 Between grid and the grid of PMOS PM1, concrete, one end of electric capacity C4 connects PMOS PM1 Grid, the other end of electric capacity C4 connects one end of inductance L3, and the other end of inductance L3 connects the 2nd NMOS The grid of pipe NM2.Inductance L3 and electric capacity C4 is for making the gain flattening of high frequency treatment.

As a preferred scheme, inverter circuit also includes resistance R1 and resistance R2, the one of resistance R2 Being terminated at the grid of PMOS PM1, the other end of resistance R2 connects one end of resistance R1, Yi Ji electricity Holding the connection end of C4 and inductance L3, the other end of resistance R1 connects the drain electrode of PMOS PM1.Resistance R1 and resistance R2 is connected across between the input of the second level and output, and resistance R2 is for PMOS PM1 Biasing is provided.

As a preferred scheme, inverter circuit also includes the electric capacity C2 for AC coupled, electric capacity C2 An end be connected to the connection end of electric capacity C4 and inductance L3, the other end is connected to the leakage of the first NMOS tube NM1 Pole.

As a preferred scheme, inverter circuit also includes for carrying out outfan every straight electric capacity C3, One end of electric capacity C3 is connected to the drain electrode of PMOS PM1, and the other end exports RFOUT as radio frequency.

As a preferred scheme, inverter circuit also includes the electric capacity C5 for bypass, electric capacity C5's One end is connected to the source electrode of the second NMOS tube NM2, the other end ground connection of electric capacity C5.

As a preferred scheme, inverter circuit also includes the electric capacity C6 for filtering, electric capacity C6's One end is connected to supply voltage RFVDD, other end ground connection.

This utility model have employed current multiplexing technology, not only saves power consumption, but also improves voltage and increase Benefit and reduce noise coefficient, there is good practicality.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of radio frequency amplifier of the prior art；

Fig. 2 is the design schematic diagram of current multiplexing type radio frequency amplifier of the present utility model；

Fig. 3 is the circuit theory diagrams of current multiplexing type radio frequency amplifier of the present utility model.

Detailed description of the invention

In conjunction with the drawings and specific embodiments, this utility model is further illustrated.

Fig. 1 is the schematic diagram of traditional radio frequency amplifier, and the first order uses cathode-input amplifier, and the second level uses Phase inverter realizes.Main thought of the present utility model sees Fig. 2, is that the second level of the prior art moves to At the power supply of one-level, and set up some components and parts on this basis to realize the optimization of circuit.

As a specific embodiment, see Fig. 3, current multiplexing type radio frequency amplifier of the present utility model, Including the first NMOS tube NM1, the second NMOS tube NM2, the 3rd NMOS tube NM3, the 4th NMOS Pipe NM4, PMOS PM1, inductance L1, inductance L2, inductance L3, electric capacity C1, electric capacity C2, electricity Hold C3, electric capacity C4, electric capacity C5, electric capacity C6, resistance R1, resistance R2, supply voltage RFVDD, First offset side VB1, the second offset side VB2, the 3rd offset side VB3, rf inputs RFIN and penetrate Frequently outfan RFOUT.

Wherein, the first NMOS tube NM1, the 3rd NMOS tube NM3, the 4th NMOS tube NM4, The input matching circuit of input capacitance C1 and source series inductance L2 composition first order amplifier.Electricity Hold C2, electric capacity C3, electric capacity C4, electric capacity C5, electric capacity C6, resistance R1, resistance R2, inductance L1, And the inverter circuit of the inductance L3 composition second level.

In above-mentioned input matching circuit, altogether grid input pipe the first NMOS tube NM1, the 3rd NMOS tube NM3, In 4th NMOS tube NM4, signal inputs from its source electrode, constitutes the first order of amplifier.And this The circuit structure design of utility model is the metal-oxide-semiconductor number that can select as required to access, it is achieved overall gain can Adjust.Series inductance L2 between the input matching circuit and the inverter circuit of the second level of the first order, it is possible to provide Preferably input coupling and reduction noise.

In inverter circuit, electric capacity C2 and electric capacity C4 is ac coupling capacitor, and C3 is output capacitance, Electric capacity C5 is shunt capacitance, and electric capacity C6 is filter capacitor.The first order that inductance L1 is connected to amplifier is (defeated Enter match circuit) and the second level (inverter circuit), it is used for leading to direct current every exchange.Inductance L3 and electric capacity C4 Coordinate for making the gain flattening of high frequency treatment.Resistance R1 and R2 is biasing resistor, resistance R1 and resistance R2 is connected across between the input of the second level and output, and resistance R2 is for providing biasing to PMOS PM1.

Radiofrequency signal inputs from rf inputs RFIN (source electrode of the first NMOS tube NM1), for common grid Structure for amplifying, C1 is input capacitance, allows radiofrequency signal smoothly enter transistor, and inductance L2 is source Pole negative feedback inductor, affects the stability of system, input coupling and the noise coefficient of circuit.If VB2 Add same biasing with VB3, then NM3 pipe and NM4 also access, and NM1 pipe is in parallel, carries together For input mutual conductance, so can increase the gain of whole amplifier, also make overall gain adjustable.

Input fit through small-signal model can obtain correspondence formula:

$Z_{in}=\frac{sL2}{1+(g_m+{\mathrm{sC}}_{gs1})sL2}$

Wherein, gm is total mutual conductance of input transistors, and Cgs1 is the gate-source parasitic capacitance of input transistors, from Above formula, it can be seen that selected good inductance and transistor size, is mated at bigger band so that input Coupling requirement is met in width.

Use the input stage being total to grid as low-noise amplifier, although the beneficially coupling of bandwidth, but relatively In common source configuration, noise coefficient is bigger than normal, and the noise coefficient of whole amplifier depends mainly on the defeated of amplifier Enter end, can be obtained the formula of noise coefficient by small-signal model:

$NF\≈1+k\frac{1}{g_{m1}{R}_s}$

Wherein, k is coefficient, transistor characteristic determine, can be seen that the increase along with mutual conductance from formula, Noise coefficient can effectively reduce, but mutual conductance is limited to input coupling simultaneously.

Owing to inductance L1 is the load of the first order, stop radiofrequency signal by this inductance to upstream so that radio frequency Signal flows to the input of the second level through overcoupling electric capacity C2.

In circuit design process, needed for the first order circuit in background technology, operating current is 2mA, second Needed for level circuit, circuit is 1mA, uses technology of the present utility model, altogether extracts 2mA electricity from RFVDD Stream, can meet the electric current needed for two-way work simultaneously, therefore reach the effect of current multiplexing.Use electric current After multiplex technique, increased owing to flowing through the electric current of phase inverter, therefore need according to practical situation device chi Little progress Row sum-equal matrix and simulating, verifying so that bulking property is optimum.

This utility model is at one negater circuit of top superposition of circuit, in the case of not consuming electric current Adding the total mutual conductance of equivalence, resistance R2 provides biasing for PMOS PM1, it is achieved broadband and noise system The improvement of number performance.Electric capacity C4 and inductance L3 produces impedance-compensated at second level input, when frequency is higher, Inductance equiva lent impedance becomes big, and capacitor equivalent impedance diminishes, and when frequency is relatively low, inductance equiva lent impedance diminishes, Capacitor equivalent impedance becomes big, therefore in a segment limit of high frequency, and input equivalent impedance all bases of the second level This equivalent, hence in so that the gain at higher frequency is more smooth.

For inductance L2, belonging to source series inductance, along with the difference of operating frequency, its equiva lent impedance is also Change, calculated by general formula and can obtain a preferably source series inductance value so that its etc. Effect impedance reaches optimal coupling in operating frequency.

Although specifically show and describe this utility model in conjunction with preferred embodiment, but the technology of art Personnel should be understood that in the spirit and scope of the present utility model limited without departing from appended claims, This utility model can be made a variety of changes in the form and details, be protection model of the present utility model Enclose.

Claims (7)

1. a current multiplexing type radio frequency amplifier, it is characterised in that: include input matching circuit and inverter circuit； Wherein, input matching circuit include the first NMOS tube NM1, the 3rd NMOS tube NM3, the 4th NMOS tube NM4, inductance L2 and electric capacity C1, inverter circuit includes the second NMOS tube NM2 With PMOS PM1；Wherein, the grid of the first NMOS tube NM1 as offset side VB1, The grid of three NMOS tube NM3 is as offset side VB2, the grid conduct of the 4th NMOS tube NM4 Offset side VB3；Electric capacity C1 for input capacitance, after rf inputs RFIN serial capacitance C1 with The source electrode of the first NMOS tube NM1, the source electrode of the 3rd NMOS tube NM3 and the 4th NMOS The source electrode of pipe NM4 connects, and inductance L2 is source negative feedback inductor, and an end of inductance L2 is connected to first The source electrode of NMOS tube NM1, the other end ground connection of inductance L2；The source electrode of the second NMOS tube NM2 Drain electrode, the drain electrode of the 3rd NMOS tube NM3 and the 4th NMOS with the first NMOS tube NM1 The drain electrode of pipe NM4 connects, and the grid of the second NMOS tube NM2 is connected to the grid of PMOS PM1 Pole, the drain electrode of the second NMOS tube NM2 is connected to the drain electrode of PMOS PM1, PMOS PM1 Source electrode be connected to supply voltage RFVDD；

Described inverter circuit also include for lead to direct current every exchange inductance L1, inductance L1 be serially connected in input Between distribution road and inverter circuit, concrete, one end of inductance L1 connects the second NMOS tube NM2 Source electrode, the other end of inductance L1 connects the drain electrode of the first NMOS tube NM1.

Current multiplexing type radio frequency amplifier the most according to claim 1, it is characterised in that: described phase inverter electricity Road also includes gain flattening inductance L3 and electric capacity C4, inductance L3 and electric capacity for making high frequency treatment C4 is connected in series, and is connected to the grid of the second NMOS tube NM2 and the grid of PMOS PM1 Between, concrete, one end of electric capacity C4 connects the grid of PMOS PM1, another of electric capacity C4 End connects one end of inductance L3, and the other end of inductance L3 connects the grid of the second NMOS tube NM2.

Current multiplexing type radio frequency amplifier the most according to claim 2, it is characterised in that: described phase inverter electricity Road also includes resistance R1 and resistance R2, and an end of resistance R2 is connected to the grid of PMOS PM1,

The other end of resistance R2 connects one end and the connection end of electric capacity C4 and inductance L3 of resistance R1,

The other end of resistance R1 connects the drain electrode of PMOS PM1.

4. according to the current multiplexing type radio frequency amplifier described in Claims 2 or 3, it is characterised in that: described anti-phase Device circuit also includes the electric capacity C2 for AC coupled, and an end of electric capacity C2 is connected to electric capacity C4 and inductance The connection end of L3, the other end is connected to the drain electrode of the first NMOS tube NM1.

5. according to the current multiplexing type radio frequency amplifier described in claim 1 or 2 or 3, it is characterised in that: described Inverter circuit also includes that one end of electric capacity C3 is connected to for carrying out outfan every straight electric capacity C3 The drain electrode of PMOS PM1, the other end exports RFOUT as radio frequency.

6. according to the current multiplexing type radio frequency amplifier described in claim 1 or 2 or 3, it is characterised in that: described Inverter circuit also includes that an end of electric capacity C5, electric capacity C5 for bypass is connected to the second NMOS tube The source electrode of NM2, the other end ground connection of electric capacity C5.

7. according to the current multiplexing type radio frequency amplifier described in claim 1 or 2 or 3, it is characterised in that: described Inverter circuit also includes that an end of electric capacity C6, electric capacity C6 for filtering is connected to supply voltage RFVDD, other end ground connection.