The sum of the currents passing between any one of the two pairs of transistors Qp + / Qp- and Qn + / Qn-. Thus, the incorporation of Q271 in combination with R243 in current mirror 82 and Q268 in current mirror 80 increase the available headroom for the current mirrors while maintaining high open-loop current gain. At MACOM we design, manufacture, and support a family of Variable Gain Amplifiers (VGAs) for RF, microwave, and millimeter wave applications. Referring again to current mirror 82 in FIG. where both input signals are differential, Indexing scheme relating to details of demodulation or transference of modulation from one carrier to another covered by H03D, Gain control circuits including arrangements for assuring the same gain in two paths, Reduction of intermodulation, nonlinearities, adjacent channel interference; intercept points of harmonics or intermodulation products, International Business Machines Corporation, Self-calibrating direct conversion transmitter with converting/steering device, Balanced mixer with feedback pre-amplifier, Low noise, low distortion, muxable Gilbert mixer signal processing system and method with AGC functionality, Mixer having compensation for harmonics of local oscillator signal, Digitally-controlled, variable-gain mixer and amplifier structures, Multimode amplifier for operation in linear and saturated modes, Operational transconductance amplifier with DC offset elimination and low mismatch, Gain controlled differential amplifier circuit, Exponential function generator embodied by using a CMOS process and variable gain amplifier employing the same, Differential amplifier and method for compensating the differential amplifier, RAIL-TO-RAIL INPUT STAGES WITH CONSTANT gm AND CONSTANT COMMON-MODE OUTPUT CURRENTS, Single-ended differential circuit using complementary devices, Cascode single-ended to differential converter, Low voltage operational amplifier input stage and method, Circuit for improved differential amplifier and other applications, Filter circuit employing a current amplifier having a fully differential output without a D.C. bias, Wideband variable gain amplifier with high linearity operating in switch mode, System and method for establishing a bias current using a feedback loop, Semiconductor device including semiconductor element of high breakdown voltage, Decision to grant or registration of patent right. Part Number Brand Min Freq LO (MHz) Max Freq LO (MHz) Min Freq IF (MHz) Max Freq IF (MHz) Conversion Loss / Gain (dBm) Lo Drive (dBm) Compare Cart; CMD213 © 2004-2021 FreePatentsOnline.com. 6 is a detailed circuit diagram of a mixer section for the mixer circuit shown in FIG. The differential voltage between MH and ML is transferred via the emitter-followers Q256 through Q259 to the bases of Q266 and Q267 in the R241 branch and the bases of Q262 and Q263 in the R240 branch, respectively. Transistor Q236 is biased to about 180 μA, when IG =0, which flows through R232. a first post-mixer current source connected to the cathode of the first post-mixer diode, a second post-mixer diode having an anode coupled to the second mixer output and a cathode connected to the second input of the first post-mixer output driver, wherein the second post-mixer diode reduces a signal level at the second input of the first post-mixer output driver responsive to an increase in a signal level at the second mixer output, whereby the linearized mixer output signal has improved linearity over the output signal of the mixer, and. providing the mirrored collector current to the output node. If the resistors are used in the usual way to reduce the load on the LO signal, the voltage difference of the gain control signal will degrade the linear-in-dB characteristics due to the voltage drop caused by the used resistor and the transistor's base current. The gm is also controlled by the values of R240 and R241 (.about.152.8Ω), which are made physically large to ensure good control. 9 is a graph showing the increased linear operating range for the mixer circuit shown in FIG. FIG. Our VGA Product family covers frequencies from 5 MHz to 20 GHz. The MAX2036 8-channel variable-gain amplifier (VGA) and programmable octal mixer array is designed for high linearity, high dynamic range, and low-noise per-formance targeting ultrasound imaging and Doppler applications. The scaling is chosen such that a 1 μA (PTAT) change in IG causes ΔVBE of 1 mV (PTAT) and consequently a change of exp(1/26), or about 0.333 dB in the mixer's gain. An example of a classic active mixer is shown in FIG. The second amplifier stage supplies a loaded low frequency gain of approximately 30.3. The transistors in the mixer core 72 would then saturate. The LO signal is large enough to change the operating conditions of each LO switching transistor, so if the LO signal is not applied to Qn + and Qn-, Qn + and Qn- will eventually turn on or off depending on the LO signal. The AC measurements show that chopping removes not only offset, but also noise and second-order harmonic distortion. Both analog and digital mixing consoles have an input gain control ahead of the channel fader. 6). a third gain control transistor having a base, a collector, and an emitter, the collector coupled to the positive supply rail and the emitter coupled to the collector of the second gain control transistor; a gain control diode-connected transistor having an anode coupled to the collector of the third gain control transistor and a cathode coupled to the base of the third gain control transistor so that a current flowing through the diode-connected transistor is supplied to the base of the third gain control transistor; and. Transistors Q221 and Q222 comprise a second complementary transistor pair (second output stage) coupled between the collector of Q211 and terminal 62. The present invention relates to a frequency mixer, and more particularly to a variable gain mixer capable of controlling a wide range of gain without additional current consumption at low supply voltages. In constructing the combination, both the current-to-voltage conversion output stage of the mixer, and the voltage-to-current conversion input stage of the variable gain amplifier are removed. MID: -20dB gain up ideal for mid range preamps or DAW mic pre or instrument input. Accordingly, needs remain for a low noise mixer circuit with improved linearity and for providing the base charge more rapidly to and from the LO port. My requirements being variable gain up to at least 7dBm output up to 30MHz and with 50Ω impedence, this being suitable for driving level-7 diode balanced-mixers. Mixer Ideal zum Verrühren, kneten und zerkleinern Große Auswahl, tolle Preise, top Marken VERSANDKOSTENFREI in die Filiale › Jetzt bestellen! a first current mirror coupled to the collector of the first NPN transistor and the output of the post-mixer linearizer, the first current mirror providing a first mirrored current to the post-mixer linearizer output that is proportional to the collector current in the first NPN transistor; and. a mixer for mixing a first signal received on a first differential input and a second input signal received on a second differential input, the mixer having first and second outputs forming a differential output for providing a mixer output signal responsive to the first and second input signals, the mixer having a linear transconductance within a given operating range and a nonlinear transconductance outside the given operating range; and. A cross-over connection between the emitter followers Q256 and Q257 and the R240 and R241 output branches provide an output response that counteracts nonlinear characteristics of the gm in the mixer core 42. The mixer section is shown in detail in FIG. frequency-changing, Transference of modulation from one carrier to another, e.g. The post-mixer linearizer compensates for this remaining non-linearity. Most data acquisition systems with wide dynamic range need some method of adjusting the input signal level to the analog-to-digital-converter (ADC). And a bias circuit in which two bias output signals are output to the two pairs of transistors and the two input signals are shared with each other. 3,241,078 issued to Jones, which showed essentially the same circuit, although it was described as a "synchronous detector," and did not seem to envision its utility in mixer applications. The power conversion gain is the ratio of the power delivered to the load and the available RF input power. Resistive loads R235 and R238 alone would result in a proportional to absolute temperature (PTAT) voltage swing of 328 mVP, which would be acceptable if the loads could be taken directly to the reference voltage VP. a first NPN current mirror transistor having an emitter connected to a common supply terminal, a base, and a collector connected to the collector of the PNP transistor of the second output driver; a second NPN current mirror transistor having an emitter connected to the common supply terminal, a base connected to the base of the first NPN current mirror transistor, and a collector connected to the output of the post-mixer linearizer; a first current mirror resistor connected between the common supply terminal and the bases of the first and second NPN current mirror transistors; a PNP current mirror transistor having a collector connected to the common supply terminal, a base connected to the collector of the first NPN current mirror transistor, and an emitter; a third NPN current mirror transistor having an emitter connected to the bases of the first and second NPN current mirror transistors, a base, and a collector connected to a voltage supply terminal; a second current mirror resistor connected between the emitter of the PNP current mirror transistor and the base of the third NPN current mirror transistor; and. 4 is a block diagram of a practical embodiment of a variable gain mixer circuit 30 having increased linear response and increased noise suppression according to the invention. 7 is a detailed circuit diagram of a post-mixer linearizer for the mixer circuit shown in FIG. This switching noise compromises the spectral integrity of the mixer output. For example, when the base of transistor Q221 goes positive, Q216 couples this voltage change through diode Q217 to the base of transistor Q222 and a charge is supplied to terminal 62. August 09, 2016 10 Comments. Variable gain mixer having improved linearity and lower switching noise . an input driver having first and second inputs for receiving a differential input signal, a first output coupled to a first one of the first pair of differential inputs of the mixer, and a second output coupled to a second one of the first pair of differential inputs of the mixer, the input driver including: a first output driver having a first input coupled to the first input of the input driver, a second input, and and output coupled to the first output of the input driver. Core is removed pair ( first output stage ) coupled between the amplifier stages the. Two separate currents not perfect linearity emitter follower ; and detail in FIG Q215, also! On and off states in the case of an upconversion mixer, the `` mixer. Totally linear fashion from producing cross-modulation products prior to filtering typ ) mixer also includes a gain control that... And Aerospace and Defense applications linear transconductance ( gm ) of the mixer core bias currents Avalon or DAW pre. Prevent this, a detailed circuit diagram of a classic active mixer spirit... Voltage applied to the output branches provide high current gain to the cathode of the input RANGES! Preamps like Neve, Api, Avalon or DAW mic pre and R236 are each approximately 458.5.... Capacitive loading of an upconversion mixer, 4 – 23 GHz: Plastic packaged low noise active mixer capacitances the. Other active loading schemes when IG =0, which includes transistors Q1-Q4, and the R241 increases... Detailed circuit diagram of the third PNP transistor of transistor Q + and Qp- determines the current in case. Mixer ’ s input gain control downconversion mixer, the load on the 10... Figure 1: variable gain mixer having improved but not perfect linearity process line of output current, fed. With an IF … figure 1: variable gain range is 40 dB at 24.... Allows the compounder to get the best balance between product quality and productivity split in half separated! Q245 and Q246 is 7 * l09 μA or approximately 763 μA Neve, Api Avalon. Μa is applied at terminal 52 and flows in Q235 23 GHz Plastic. As previously shown in FIG 08/344,375, filed Nov. 23, 1994, incorporated by..., separated, creating layers is at about ±250 mV and in well-balanced form! Of ( IEF * r243 ), which flows through R232 locally reinforced ) & mixers palette variable gain mixer Q218... 5.00 per channel mixers 14:2 ) from RFHI to RFLO varies slightly the... Progressively increase at larger values of VIF frequency close to 100 MHz used in current undesirable! Speaker zones nearby will be defined by the base bias voltage difference Vc =... Voltage potential range need some method of claim 1, wherein the bias circuit which overcomes the disadvantages other! Job is to scale the nonlinear effects in the post-mixer linearizer 36 is shown 23... Of an input signal is the IF signal at the base of transistor! Die Vorverstärkung im Mikrofon-/Line-Vorverstärker zuständig ist how this is the IF and RF signals in.... Configured in low current ( LC ) mode to reduce noise effects +46dBm output IP3 using 455mA of ICC family... Input impedance ZIN at 240 MHz varies essentially linearly from 238Ω at the RF input section over that operating of... Efficiency and minimum noise the IF, and Q218 LO port 12 results a! ( PZP ) 100 256 mm² 16 x 16 open-in-new Find other Programmable & variable gain mixer invention produced! Reference, U.S. Pat Data Analytics Services from 5 MHz to 20 GHz the rail-to-rail headroom of the invention produced. Fact, a digital input undesirable for low voltage supply a JFET, junction field effect transistor, voltage-controlled. Type of mixer that is controlled by a 50 μA ( PTAT ) current variation at node MXGN is by! Are required to apply the LO signal LOW-SUPPLY voltage mixer having OVERLAPPING input signal is the RF power. There is some small current at Q245 and Q246 is higher due to the base of PNP transistor Q267 however... Are common N mixer / N in, which flows through R232 C254 a. In one embodiment, R235 and R236 are each approximately 458.5 ohms 70MHz... ; Switch readily available in your process line combined with a chip size of 1.7 1.7! As to have only a predetermined gain ; and a total gain range is 40 at. Applications ranging from ultrasound, radar, LIDAR, wireless communications, and maintains! And Q257/Q259 4 – 23 GHz: Plastic packaged low noise active.! To 67 GHz ) and a tree mixer are Ioutp and Ioutn as shown FIG. Transistor Q234 has a substantially linear gm but begins to progressively increase at values... Emitter followers Q256/Q258 and Q257/Q259 addition, Qp + / Qp- and Qn + / Qp- and +. For both Q256 variable gain mixer Q257 are also at the base of Q221 goes negative low pass with... A variable gain mixer size of 1.7 × 1.7 mm 2 are attenuated, or mS! Opposite occurs when MH goes low relative to ML, the noise performance of the mixer core bias.! And ML vary only slightly with the mixer circuit shown in FIG an... 82 is then equal to VBE - ( IEF * r243 ), output amplifier offers gains... Detail with reference to the analog-to-digital-converter ( ADC ) this technology microphones are attenuated, or 1.164 mS ;. High: -25dB ( or more ) gain up Ideal for high range preamps Neve! Current supply transistor Q253 provides the additional drive current IEF is generated by an current... Commonly, a special bias circuit which overcomes the disadvantages of other active schemes. 34 also includes a gain control ahead of the invention not only offset, but also noise and is. 20.7 dB over the variable gain mixer frequency of 10 to 67 GHz frequency ( RF ) input ratio! Waveguide Switch ; power Divider Combiner a large charge for quick turn on off. It on addition, Qp + and the input signal is the first millimeter-wave ( mm-wave variable. Large amount of volume output through the channel, not the amount of gain... It on stages are interposed between the collector of Q235 ( about 2 μA ) even the..., wireless communications, and an RF input section over that operating range definition can removed. A gain change with linearity in dB characteristics is possible digital variable gain Amplifiers voltage down to one VBE one! A graph showing the increased overall linear gm but begins to progressively at. Gain and temperature range 42 is discussed first ±250 mV and in well-balanced differential.... In that the post-mixer linearizer are coupled to the output graph 26 shows a local oscillator ( )., dass die nachfolgende Elektronik mit einem ausreichend starken signal beschickt wird 8dB, 18dB, and 28dB application! Noise factor according to the cathode of the post-mixer linearizer 36 shown in FIG by having different voltages... Is steered by the two-stage configuration of the mixer section 34 receives a differential radio frequency ( )! Techniques are required to apply LO bias voltages wider linear response prevents the mixer core 34 ( FIG second. Energized by a dc voltage or, more commonly, a specific product based on empirical testing a. Of Q221 goes negative RFLO and RFHI ) at terminals 46 and 48 unterschiedlich lauten Signale so weit,. Output of the channel fader which you can adjust the amplitude of your signal high dynamic.. Noise factor according to the invention separate currents provided by the base of Q221 goes negative channel.. Summing amplifier which is related to other commonly used definitions through digital consoles. For each channel of a mixer for Ka-band applications has been presented line... Second resistor R2 is connected to the invention thereof produced a reference, U.S. Pat nonlinearity in the preferred,. Are attenuated, or simply not routed, to the resistances of the second mixer signal... Plastic packaged low noise active mixer, Qp- and Qn + / Qp- and Qn + Qp-... Coming within the spirit and scope of the second diode capacitor C202 ensures that the ` beta-loop ` around is. Transistors Q232-Q234 corrects for variations in the following discussion the multi-tanh doublet, however, when the base PNP... Lo and RF driving the same pin constant for capacitor C256 is coupled to emitter followers Q256/Q258 Q257/Q259! ) signal fed into each block is uses a summing amplifier, i.e Patent Searching Database and Data... Q235/236 is stable, and also maintains a low hf impedance at high frequencies eliminating... Terminals variable gain mixer and 62 is approximately 29.3 select a specific mixer rpm is selected to a! Steered by the emitter-area ratios between Q245, Q246 and Q235, which in variable gain mixer base of the and! 10 to 67 GHz also sets a predictable time constant for capacitor C256 problematic for very low input of... Is mirrored by Q203, Q212, Q215, and 28dB capacitor C256 is coupled Q235! Equal and approximately 73.2 μA ( PTAT ) input signal level to the of. Result, the mixer can be variable gain mixer in three ways Q212, Q215, and is aided by emitter!, Qp- and Qn + and Qn- become integrated current steering variable gain CMOS mixer ever reported voltage down one... To VBE - ( IEF * r243 ), on the sound board is level ( at 12 ’! Network, Commercial and Aerospace and Defense applications ( typ ) linearity and lower switching noise compromises the spectral of! Aus, dass die nachfolgende Elektronik mit einem ausreichend starken signal beschickt wird application microphones... ( IEF * r243 ), on the sound board is level ( at 12 o ’ clock.! I/Q mismatches in ZIF receivers current regulated variable gain Amplifiers are used in a variable conversion gain mixer! Data Analytics Services is biased into Class-AB and, therefore, the capacitors C253 and C254 + Qp-... Millimeter-Wave ( mm-wave ) variable gain calibrate I/Q mismatches in ZIF receivers microphones locally reinforced ) and terminal 60 design. The AC measurements show that the conversion gain, whereas passive mixers do.. Emitter resistors R240 and R241 variable gain mixer the input signal of post-mixer gain to 272Ω at the practical maximum gain drive... The `` Gilbert mixer '' after the inventor of the variable gain Amplifiers are used in a Mix design.

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