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34 Threads found on Variable Attenuator
Mixers are generally driven hard by LO port and impedance matching is not necessary because input impedance is very variable at LO port due to hard driven rail to rail swing signal level.Matching can be considered for RF/IF port so small signal input impedance can be taken into account.However matching is not a "must" for those ports, except some c
ALC done for a 3 decades variable oscillator it is a challenge. The constant amplitude at the output cannot be achieved without using a gain/buffer or attenuator stage controlled by ALC. Perhaps for this wide frequency range is good to use a PIN attenuator controlled by the ALC circuit. Generally PIN attenuators doesn't (...)
Common protection means are current limiting to protect against output shorts and overtemperature shutdown. A well designed audio amplifier shouldn't get overheated with any usual audio input. I don't believe that variable gain is an appropriate means against overload. If the user want's it pretty loud, he'll turn the volume control though. A
The remote controlled volume control on your TV. The attenuation signal is a variable DC voltage that drives an attenuator.
You can use a VGA (variable Controlled Amplifier) controlled by an AGC circuit (Automatic Gain Control). If your sync level can be lower than -15dBm, you can use a variable attenuator controlled by an AGC circuit.
Try connecting the two radios with coaxial cable and variable attenuator. You should have an estimate of the Rx sensitivity, see how close you can get to that over cable. If that is close to what you expect, then you can rule out the radio and digital processing, and the problem is either the antenna, or something over the air.
First problem I think is to use a DVM on fluctuating voltage. Use an oscilloscope, and use a variable attenuator before your detector! Typical microwave sweep oscillators deliver +13...+15 dBm output, which can kill your detector in seconds. It starts by heating it- this looks to you as a variation. Sweep oscillators also need adjustments and do
Hi, I want to make a variable attenuator by using MA4FCP200 Flip Chip PIN Diode. Data sheet for this diode is here: . I saw in a journal paper they made a variable attenuator with this PIN diode. But I am unable to make a pin diode in ADS with the given value in the data sheet. some of the param
I require an attenuator that is capable of attenuating a signal from 0 to 250 MHz. The signal could be a dc voltage or some waveform. I have seen some digital attenuators that are used for RF and was wondering if these would work. Otherwise I would need to design my own so any thoughts on a circuit would be appreciated. TIA Jon
Hi, i want to build a Broad-band active variable attenuator from this tutorial. Here they used a MACOM MA4P202 PIN diode in chip form for building this attenuator. I want to know If I o
I want to use HSMP-481x diode in my variable attenuator circuit. Can anyone give me the requiered parameters to use it in the ADS? Can I use the PIN-Diode model which are available in ADS or I have to use the diode package? I f I have to use the diode package then I need a package schematic for HSMP-481x. Can some one give me a schematic for that?
I am trying to build a PIN diode controlled variable gain attenuator by using two branch line directional coupler for my master's thesis at 7.5 GHz. In one journal they made such attenuator from 0dB
Hi - I'd like to find a circuit that will divide an input signal based on a control signal. I need the operation to be linear. A transfer function like this would be ideal: Vout = (Vin / Vgain) * 1 V Any suggestions for how to do this?
can one provide some literature regarding variable gain amplifier. or simple shematic on how would we achieve variable gain.
I suggest you to study a textbook on microwave techniques. PIN diodes are special type of diodes which do not rectify the AC (microwave) signal but they vary their resistance by an applied DC current. You can find instructions on building PIN attenuators as "white papers" by Agilent and other PIN diode manufacturers. Designing an attenuator at 2.
Helo everyone, I'm a telecommunications student and I recently enter on a project that consists on constructing a printed circuit which can attenuate (or not ) a AC signal. The attenuation should be controlled by a DC Voltage. The working frequency should be 2.4 Ghz. I already found some data in the internet. I would be really gratefull if some
1)current thru loops of wire forms magnetic field 2)you are wrong, they are the same 3)vary supply voltage to vary device compression point or add a variable attenuator AFTER oscillator 4)741, do they still make those? All devices on this planet show non-linear characteristics.
Which part of variable gain amplifier can be used in this field? spec: frequency band: 50~860MHz impedance: 75 Ohm OIP3: 38dBm gain maximum:at least 15dB gain adjust range: 20dB Thanks
Well, the shape of the resistive card is, or course, important. I would vary the length until it is more uniform in loss over frequency. I would play with the taper on both ends until it has a good return loss over all frequencies. If this is intended to be a "variable" attenuator, you need to move the card in and out of the waveguide thru a s
VGA=variable Gain Amplifier will fit your requirements with an AGC loop.Otherwise, the amplifier can not understand how much signal has arrived its input and it can not see how much intermodulation will be produced. LNA+AGC system should be considered.
hello what is VVA (voltage variable attenuator) and its role in a power amplifier system?
This is manual for R&S DPSP variable attenuator. It includes operating instructions in german and english as well as parts lists, schematics, PCB layouts etc.
Using a FET as a voltage variable resistor maybe a simple solution. By changing gate bias you can vary the "resistance" between drain and source. Hope this helps. S. H.
Hi i would like to design a variable attenuator pad (~18dB) using @DS Momentum Simulation. Did anyone have any good suggestion regarding the attenuator design info and link to design on that in microwave circuit? Look at the attachment file. May be, it will helpful for you.
Dear all: I am looking for some voltage variable attenuators (VVA) candidate ICs. Can someone please show me some of the sources that make VVA? Specifically: 0 - 3V control voltage 3.3 V supply voltage 35 - 40 dB attenuation Freq from 0.8 GHz to 2 GHz Extremely high IIP2 Phil
Hi All, I am trying to desing a VVA using 0.35u bulk cmos, can anyone give some advise about the design or layout. Thanks
There are many commercial variable attenuator designs where fixed attenuators are switched in and out. If you have the following attenuators: 1dB, 2dB, 4dB, 8dB, 16dB, and 32dB. Then you can realize a variable attenuator in 1dB steps from 0 to 63dB. Check out the following data (...)
Hello everyone, I am new to ADS and I encountered a problem. I wish to simulate variable attenuator using PIN diodes. when I place the PIN diode and Trans Simulation and runned simulation The software gave me an error in the simulation window: " "NLPIN1" is an instance of an undefined model "NLPINM1" " My question is, How do I
You will have to us an external variable attenuator. If at the input, it will degrade the noise performance. If at the output, it will degrade the distortion performance.
Hi all ! I am wondering if any of you have been using PIN diode circuits as variable attenuators... The actual question is whether or not the diode's behavior as a variable resistance (which is exploited in the variable attenuator) is very sensitive to temperature variations... In the HSMP-381x (...)
Inside a waveguide there is a piece (rotary) of dissipative material (not metallic). The Electric field and the piece of metallic material form an angle phi. The value phi is the variable of the attenuator. The component of the E field parallel to the piece o material (phi=0) is dissipated; at the output of the waveguide I'll find only the ort
You can also make your own by putting a variable attenuator in front of a fixed gain amplifier.
I do not know of one. You can use a variable attenuator before or after a fixed gain amplifier. Putting it before degrades the noise but allows high signal levels. Putting it after has minimum noise but the amplifier may saturate on high signal levels.
Hi Baidu, That's easy, add an continous, variable attenuator after the sig. gen. You can get your desired.