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active biasing is often used in rf power amplifiers where emitter or source is grounded. Such amplifiers are usually dissipating heat. To improve temperature stability negative dc feedback is used to keep average collector (drain) current constant. Feedback is usually made with PNP transistor.
HI, I am interested in a LNA design for low noise. I am told to use an active biasing to minimise the noise figure and also have a lower VSWR ratio. Does anyone have idea what is active biasing and where can I find information on it? Thanks for the help Rula
HI, I am interested in a LNA design using BJT for low noise. I am told to use an active biasing to minimise the noise figure and also have a lower VSWR ratio. Does anyone have idea what is active biasing and where can I find information on it? Thanks for the help Rula
Hi, everyone. I have a question about what kind of op-amp I should use to design an active biasing for a power transistor. Basically the I am going to employ a sensing resistor to capture the power supply current from Vcc to transistor. The voltage drop is then compared with a reference voltage by an op-amp. And the op-amp output is connected to
Im checking out this FET type LNA IC (ATF-54143) that offers two different schemes of implementation (passive biasing and active biasing) What is the difference between the two? Is one scheme better than another in terms of providing gain, rf output?
Hello, Did you have a look in their web page (Minicircuits) or the data sheets. If you are talking about a Minicircuit active mixer the power is required for the internal amplifier module so current consumption will depend on the model. Passive mixers don't require any biasing. Cross
There is an IC from infineon for an active bias circuit. i am not sure that you can use -0.2 v or not.
Can anyone show me how to setup the simulation in AWR for a BJT frequency multiplier? I am using an active biasing network also. Thank you, ks
Hi One of the reasons I am interested about this, is regarding active biasing. I have found some articles, that say that active bias can be difficult to achieved with class AB amplifiers. I have attached a paragraph from an article discussing this. I have seen different ways to do active bias. One is where we use a (...)
Hello! I´d like to design a limiter with pin diodes. When I use two pin diodes (without active biasing) the point at which limitation starts is to low. The limitation begins at 5dbm - I need it at 30 dbm. How can I solve the problem? Any usefully documents? nice greeting :)
try active bias circuit, it is more stable voltage for temperature change.
Suppose in your second stage you have NMOS common-source amp and PMOS current source load. Then your second stage biasing current is mainly controlled by the PMOS current source, and actually Vgs of the NMOS is determined by this current. However if the opamp is used as a feedback amplifier, the common-mode feedback will automatically adjust the Vg
i need a famous topolgy for designing an active bias network for an LNA operating at 11.5 Ghz in an LNB .. i found a one in Gonzales book but i need a good application note about this topology... Another question....will the noise figure be degraded so much after biasing the transistor with this topolgy ?! THANKS IN ADVANCE..
walters, Why do you have to set Baising for a Tube or transistors? biasing is required for any transistor that is designed to function as an amplifier, not a switch. biasing sets the DC operating conditions, operating region of amplification and AC swing. What is the Operating Stage for a Tube? I don't quite
4th edition of Gray and Meyer teaches you basic to advanced biasing circuits. See active current mirrors chapter. I guess, it is chap.4. Hope this helps.
bias 1. Any parameter of which the value is set to a predetermined level to establish a threshold or operating point. Although it is common to think of bias currents and bias voltages, other parameters (e.g., capacitance, resistance, illumination, magnetic intensity, etc.) can serve as biases. 2. In a high-fidelity audio system, a circuit in
hi knack, In electronics every active device, ex. transistors, needs a contant dc current and voltage on it to work properly. Setting this current and voltage level and giving it to the device is called biasing. biasing determines a device's operating point. What i meant by operating point is: for ex. by bias level you can change an (...)
hi all, wanna know the difference between active and passive mixers (like how the gate n drain biasing will be in both) n which one is better??
Hi, In reference to u r ckt, M12 and m13 act as pre charge devices which pull either of out- or out+ to vdd (its explained how this happens in CS amp with diode/active load in razavi) If you use a resistor to do this job, there will b a drop across it so u r output can't reach vdd any time. which is not the case when u use a pmos device.
Hello, can anybody help me? I design pulsed power amplifier and I need help with biasing TIM8596-15. How can I do temperature compensated active gate bias and how can I set right drain current? Pulse width is 300ns-30us, D.C. max 20% and PRF 3-50kHz Thank you
Hello, You can do this biasing very easy & simple just use the BIASTEE elemet available in Microwave Office (MWO) (Elements => General => Passive => Other => BIASTEE) Which is just Ideal Bias Tee & which does not affect the input admittence... See the attached picture for the setup for your active Capacitance circuit DC biasing...
hiii.... I used ac simulation to find my inductance and Q factor..I will recheck the s-p analysis later. There is another problem....I implemented a cascode active is meeting my specs....Now i have to implement tunability...What do you suggest is d best way...i'm thinking of changing the bias my g
Your bias current changes with the supply voltage, this explains why you see a bigger variation with power supply. You should bias your active device with a current source to keep the bias current constant.
Hi I was searching if a transistor is linear device or not. A linear device has a linear relationship between current and voltage (Ohm's law). I'm a beginner in this electricity and electronic stuff. So, please keep your reply simple. Thanks. While searching I found this: We will operate transistor mainly in 4 regions, namely
Hello biasing the transistor meaning setting it in the right position of the amplifier operation region. in bipolar transistor amplifier the bipolar transistor has to be in the active region and is done from the DC setting which nothing but the biasing. the exact point of the setting is the Q point, in order to have maximum amplification we (...)
What is the importance of active and passive feedback and advantages
Hi all I'm trying to design a low noise amplifier with these specifications: Frequency: 1.5GHz Gain>15dB noise figure <1dB unconditionally stable K>1 I'm using Avago ATF-34143 HEMT as the active device. I'm quite new to this, I've found tons of stuff online about LNAs but very little on how to design an appropriate bias network. Firstly I
active Filter Design Info:
I need a book about active circuits. Please if anybody has a book or a link where i can find it there, tell me about. There are books for sedra,Huelsman ... but i couldn't find any free on the net.
Who has the schematic of active antenna loop through of DVB_C tuner? Such as THOMSON DCF8716 Thanks ynhe
I am looking for a low noise inverter chip (8pins) to generate the negative voltage for biasing GaAs Fet's gate. I tried the Maxim and Linear Technology chips. They performed good but they did'nt accomplish with the temperature range requiride. Does somebody suggest me some other manufacturer? Thanks in advance NandoPG
Hello, I was looking for information on the DIY construction of probes. I already noticed another thread on this board that listed this url: Good stuff :) Now, while 1 GHz passive is very nice, does anyone know of any sites that explain the construcion of say an active 2.5 GHz probe? Yes, I know th
Hello I want to conver a 0-10Vdc signal to 0-2.5 Vdc .I do it by two resistor (1%)as a passive voltage divider,Both the linearity is not good and in some region of full range the value of nonlinearity is high.If I use a .01% resistors the problem may be solved but the cost is too high. I need to know is there an active solution with opamp fo
Hi together, is anybody out there to provide me w/ some paper w/ respect to design and analysis of active RC biquad filters (e.g. CMOS implementation) and digital biquad filters realization. Should help to judge different types of implementation (analog vs. digital). tia & br muppettoon
I thought "active" was his question here, not the simulation of some patch. Am I missing the point?
All, Where is the "active topic menu" on Elektroda? Was it removed? LLCD
What do you mean on "active power divider" ?
Anyone have infornation about RF transister biasing? Especially, class B,C.
I suspect you mean to convert from differential to single ended with one op amp. Then elliptic filter and convert back to push pull. The Nuhertz filters are available for a 20 day free trial. This program can design passive and active filters.
active is almost as fast as Modelsim and is much easier to use. It also has many features that Modelsim doesn't. It's equal to Modelsim+HDL Designer.
Does there anyone has document on active balun design?It's a distributed active balun,which has the form like a distributed amplifier. Thx very. rgz, Needbias
I need kit consists from active components + PCB for XxS510PP. Send me your quatation to PM
Hi Is there a way to detect the presence of an active cell phone? The idea is to detect a switched-on phone where such a device is not permitted. E
There is a system level thing to keep in mind with mixers. They are more distortion producing than amplifiers and you should block out your system so that they have the minimum signal level that allows your system to function. Usually, you put a bandpass filter in front of it and have only enough RF amplifier gain to set the system noise figure.
Anyone knows how to calculate active filter noise figure? thanks.
Anybody knows how to design: active 6Hz Bessel Lowpass filter? 1st order, 2nd order? Frequency is very low 6Hz. and thousands of thanks!
Does anyone knows how to design a biasing voltage reference circuit with enable/disable function in CMOS? Normal stable biasing reference point are generated from a chain of equal size PMOS loads. How can we improved this with a enable/disable circuitary which is stable in process and temperature variations? :?:
I am using a bjt for LNA designing .Which biasing network is most suitable to achieve minimum NF and K>1.
what is phemt?what is the biasing condition of phemt?Is its biasing condition is same as N channel FET? pHEMT (pseudomorphic HEMT) is basically a FET with a different epitaxial active layer & doped such that the electron motion is less random.The transconductance of these devices are higher (hence have higher gain) as