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282 Threads found on Input Signal Mixer
Take a standard differential amplifier, or mixer. Usually, the RF input signal is injected into the source of the transconductance stage. My question is, what negative effects will there be if the RF input signal is injected into the gates instead, and why? Thanks!
when multi-signal input mixer. I want to get the power of the intermodulation signal. The HB method can't get the right answer. could you give me a good model to simulation it.
Basically the 50Ohms of resistor would be for input matching and the capacitor serves as a dc block from the input signal. Rgds
There is a hard fundamental limitation. The sum of the powers of the output signals cannot be greater than the input signal. The absolute minimum loss is with just the sum and difference outputs (which are equal power) which produces a 3 dB loss. When the diodes are saturated there are many more output products and so the one you want (...)
As a first indication, when calculate parameters of mixer linearity, have to use the same definitions as for LNA. LO signal is considered as part of the mixer, and not as an input signal.
The mixing action depends upon nonlinearities. At lower supply levels there are probably more nonlinearities for a given input signal level.
You can convert from differential current to voltage and then do the combining of the voltages in the usual op amp way. To do the differential current conversion, use the traditional four resistor-opamp circuit and do not use the two resistors that go to the source of the signal. Use just wires. The current-voltage conversion factor is then th
You don't generally need to match LO port of Gilbert cell to drive LO signal. If LO signal is sufficiently high, for instance 200mVpk or more it will work. LO port is namely has high input impedance. But RF port, small signal s-parameters will be enough to match to the source. In fact some mixers have (...)
Hi Guys: It was stated in a Journal that the Noise Figure and Conversion Gain in an Up Cnversion mixer utilized in the Transmitter topology is not a key parameter due to large input signal. Some arising questions are: 1. If NF is not the key parameter, how does the effect of flicker noise which manifest around 1MHz in this (...)
Dear All, I have a question about the LO frequency selection for a mixer used for up conversion. I have a IF input signal at f1 and the desired RF output signal is f2. There are two ways to get the RF output. One way is to use LO frequency at fL, f2=(f1+fL). The another way is to use fH, (...)
At the second harmonic of the input signal (RF?) the parallel tank is open. So the input stage transconductance is not impacted. So there is no significant mixer rejection at 2*RF. Because the conversion of gilbert core cell (4 NPNs) is low on the second harmonic but high on the third I suggest to make the parallel tank by (...)
As your circuit is characterized by voltage (and not power) gain, be sure you appy and measure correct sources and loads. A common practice is to talk about equivalent power levels. for example you can express the input voltage as equivalent power to 50 Ohm load. To do so, take the 50 Ohm source and connect to 50 Ohm resistor. Take the input volt
I am designing a double-balanced mixer and think I need a balun to be implemented in the RF input for characterization purposes, and found this circuit that converts from single-to-differential. I simulated it and got the differential output expected. - How this circuit works, if there is no input signal in one of its (...)
Dear all : We all know mixer input is LO/RF , LO is upper , RF IS bottom, IF switch LO/RF sequence , RF is upper , LO is bottom what will happen ?? If someone have reference meterial , please tell me .. Thanks ..
I think you mean difference between frequency multiplier and mixer; they have alot of similarity but the main difference between them is that in frequency multiplier only one signal is implied while in mixer we need two signlas as source. In both of them to approach our need we drive circuits to nonlinear area to produce the harmonic of (...)
in transmit path:I and Q signals are mixed with the same local oscillators(LO) which have a 90 degree phase shift.the combined sigals are transmitted in the air through antenna. in receive path:the input signals is mixed with local oscillator signal at the carrier frequency in two forms,one is at an arbitrary zero (...)
in transmitter u get an already large signal and i guess u mostly care about linearity not gain but in the Rx the signal is small (comparable to noise) and u care about gain and NF as any block in the front-end so that u don't educe the overall NF of the system and i think u care about lineairty but not like the upconversion mixer as the (...)
I want to design a single-balanced mixer using CADENCE, RF port is 1.8GHZ (single input) LO port is 1.7GHZ (differential input) IF port is 100MHZ (differential output) I use a port cannect to the load as the IF port. (both port terminals connect to the (...)
1.) You can use dual gate fet to built an active mixer, the isolation is alright. An appnote is attached for your reference. 2a.) IF frequency of the mixer suppose to be unchanged. Therefore, you should change the VCO frequency ( normally control by PLL ) in order to keep IF coustant. This is what normally do for rf modules. b.) Change VCO
dude one of the circuits that i posted (the FET model) have 2 inputs and you just have to feed the two waves that you are talking about.... hope it is helpful....
Designing a circuit that only mixes is not all that difficult. You already have an oscillator which oscillates at a desired frequency. You give this to the Emitter of a BJT and Your input signal should go to its base. The output is obtained at the collector, after filtering the desired harmonic out. Cheers
Hi all, Currently I am designing down-converter for power line carrier application. One of component in down-converter design is analogue mixer. This analogue mixer would be used to mix (RF) input modulated signal from power line (20KHz - 1MHz) with LO clock signal in order to frequency shift (...)
Dear all, I am doing dual up conversion mixer simulation using SpectreRF simulator. However, I do not know the setting of NF and voltage gain simulation. I hope you could give me a step for reference. My simulation input is as follow: RF input: DC with a band from 0 ~ 250MHz (the RF input (...)
Microwaver, We need more information in order to be able to help you. Here's what ideally I'd like to see in order to make any judgement: -Circuit Schematic with Voltages/Currents annotated -Block-by block breakdown: 1) What is the NF, Gain of a single gilbert cell? 2) What is the NF, Power output of the LO amplifie
dear all, if the pos/neg input of RF signals to passive mixer are with different amplitude, what will happen to the IF signals? since the double balance mixer could balance the output signals, so we can get two IF signals with identical amp but -180 degree, right? then (...)
It seems we have to work a lot to come out... First: LNA+mixer sim. You do not use a local oscillator for the Gilbert cell. This is wrong for the proper mixer operation. Furthermore the bias of the Gilbert cell is wrong and 18V in the LNA is very high!!!! It is not clear how you biased the mixer current mirror. My first suggestion is (...)
The HMC483MS8G & HMC483MS8GE are high dynamic range passive MMIC mixers with integrated LO amplifi ers in plastic surface mount 8 lead Mini Small Outline Packages (MSOP) covering 0.7 to 1.4 GHz. Excellent input IP3 performance of +33 dBm for down conversion and +30 dBm for up conversion is provided for 2.5G & 3G GSM/CDMA applications at an L
Is it possible for a rf amplifier, the gain decreases with increased input signal (in heavily overload condition, far past the compression point)?. I don't have enough equipment to verify this behaviour.
Being the first time use the mathmatical model of mixer in simulink RF blockset,I made a simple model to check out the conversion of the spectre of the input signal,in my case,the input is composed of two sinus,who have a frequency of 100Mhz and 300 Mhz,the F_sample is set to 2Ghz,the LO frequency of mixer (...)
Hello I would like to know how to simulate a mixer in Spectre PSS? the LO and RF signals are derived from AUTONOMOUS oscillators, so there is no input signal sources except those oscillators. how to setup the PSS? should the oscillator tab be checked? what signal names I should put?
Dear all, I have question about the quadrature mixer NF simulation setting. I hope anyone could teach me. The attached picture is the NF simulation setup for quadrature mixer. In my design, it has two input ports (Port 1 and Port 2) and generate quadrature signal for the mixer (...)
As the resistive mixer has only 4 mosfet which act as switch, the input impedance is time-variant. How can i estimate the impedance?See the followings surely. [quote=s
i am dedsigning a mixer for a Superheterodyn receiver . The input signal is wideband from tens of MHz to tens of hundreds of MHZ(almost 1 GHz). IF is about 300MHz。 The mixer needs high IIP3, and low NF. The mixer need 50 Ohm input and output match. This is the (...)
Hi, In receiver design, there is well known question, reciprocal mixing. The reciprocal mixing requirement is usually expressed as the interference product produced by reciprocal mixing is below or equal to the floor noise at the ouput when only the MDS(minimum detectable signal) is apply to the input. So the constraint on LO phase noise is PN=
I have problem with this mixer on picture. Is it normal that after BF981 IF amplitude is lower then input signal in mixer (70MHz)? Would not this kind of mixer have some small gain? For XTAL I use 20MHz crystal instead of 60MHz (because I can't find 60MHz crstal) , I have oscilation of 60 MHz on G2, but I'm (...)
I am designing an lna and mixer for zigbee receiver. my lna gain has varitions between 26.9db for -91dbm input power to 29db for -20dbm!my lna is fixed gain apparently!. but it's gain variations isn't's gain variations file has been attached here. my lna's output impedance is 772ohm. I think it is ubnormally very's nf is 2.6db ,
To find the SNR, you need to know the signal strength on the input of the mixer (signal Generator) and the output of the mixer (Spectrum Analyzer), but also the Noise Figure (Noise Figure Analyzer) of the mixer. Then calculate your SNR.
If you use Resistor, the current won't be constant enough, this will change the OP of the mixer.. Thanks for you reply) So you mean that there would be additional power consumption, especially at large input signal, as i understand. That's not a big penalty.
Hello Every one, I want to design a analog mixer with 0.18um BICMOS process. The mixer is used to be one module in the whole chip. One input signal of the mixer is a wide-band signal, for example , its bandwidth is 50MHz. The center frequency is variable between DC and 2GHz. The other (...)
Consider the quadrature mixer as shown below. The frequency domain representation of the input signal x(t), X(f) is as shown below. Assuming that f2>>f1>>fb, draw the frequency domain representation of the signal at points a, b, c, d and e. 64380 I am not asking you to do this for me. I would maybe like someone to
A mixer is in principle a multiplier; it multiplies for instance the local-oscillator signal with an IF input signal. Then pairs of multiples are generated in frequency spectrum. We typically choose one of them, name it RF and use filters to suppress all others. Such action is named "upconversion" and can be used to (...)
As your circuit has no DC supply, the mosfet will act as a switch that will go on and off in the rythm of the LO signal applied to the gate. This functions as a mixer, as it is like multiplying the input signal with square wave with amplitude =1 (assuming sufficient LO drive). The conversion loss is greatly affected by (...)
THere are more parameters to consider. First, your down-converter mixer will be a part of a receiver. To function, you need to know the type of signal modulation and transmission data rate. This requires a certain receiver bandwidth. The bandwidth determines the input noise power, the "N" in signal-to-noise ratio. Second, to (...)
Hi biff44 again. So, after the mixer i put one filter to cut the unwanted zone. So instead the mixer and the filter you propose a single modulator. As i understand the SSM wil need also a filter to cut the unwanted L.O freq=30.1MHz. So why a SSM and not a mixer? Also the SSM that i see here
How to define "input power" ?? It's unusual... Power is defined with impedance so you don't know input impedance hence you can not see "input power" since you don't know impedance. PSS doesn't give you any reflection information, how do you consider that ??I think you make a serious mistake..
On 2002-03-20 05:40, BA1DU wrote: Does anybody have idea on design broadband mixer? need to convert a fixed RF input to a variable IF output from 10MHz to 2 GHz. Thanks! No
This is generally unwanted thing. But to escape from that is opposite of the nature of the material. If you use a passive circuit at the input of a receiver system , NF will impact directly to NF of system . In fact , it really depends on many factor , bandwith , gain etc ( remember Friis formula ). Sometimes they should be used with amount
Why you need LO port input impedance of Gilbert Cell mixer ? Under the high level signal condition , input impedance of a Gilbert cell mixer varies by LO signal amplitude. Regarding to saturation status of bipolar transistors ( varies proportional to tanh ) input impedance (...)
Is there anyone who knows how to use the LSSP with ADS to measure input and output impedance of a mixer ? Thanks
Hi 7rots51, Create a local-oscillator in the range of about 5.6GHz (e.g. DRO oscillator). The bandpass-filtered input signal from a horn antenna and the LO signal is given to a mixer-diode (balanced, e.g. HSMS-8202). The output-signal is now in the range of 200MHz. This signal can be fed (...)