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Rf Power Amplifier Stability

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29 Threads found on Rf Power Amplifier Stability
it is easy to check the stability of the power amplifier,follow the following steps: 1) link the signal source and the power amplifier and the attenuator with the spectrum analyzer. 2) set the power amplifier analyzer full span 3) then turn on your (...)
Hi all, Which kind of substrate the designers use as PCB in RF power amplifier circuit? I give a picture below
Hi, I am designing a 30W Rf hybrid microstrip power amplifier in S frequency band. I encounter stability problem that's why I need to implement serie resistor on the RF path to improve the power amplifier stability. I am looking for a 10-20 ohms chip resistor able to support 1 to (...)
Dears, I am working on RF power amplifier. DC bias, small-signal frequency response and stability are just fine. The problem is that the output power above certain limit it reaches the expected value then immediately drops down by several dBs, however cooling is OK (heat sink and air flow). Any suggestions? Thanks, WM3
I made stability simulation and it's ok. It seems stable at every input output impedances. Here is additional information. The amplifier is LDMOS MRF6S27015GNR1. I commonly used the test circuit of the device. I transformed the impedances compatible to my dielectric substance fr4 , 1.6mm thickness where the test circuit was built in taconic rf-
Dear microwave specialists, I am designing an RF power amplifier operating at C band. I am simulating some gain (spikes) at low frequencies up to 4 GHz. The transistor itself shows obviously a very high gain at low frequency and it appears difficult to me to lower this gain with the matching network. The power amplifier (...)
Hi all, I'm drawing the layout for a rf power amplifier and I would like to know if there are other ways of optimizing the transistor (other than finger) to reduce the parasitics of the transistor? What are the techniques used normally for drawing transistor layout in rf power amplifier?
I am assuming that by intermittance you meant that you have intermittent output power cutouts. This type of intermittence might be caused by excessive current and/or voltage across the RF capacitors in the RF circuit in itslf and/or in the RF by-pass network. If it is the case the capacitor's ceramic will be slowly cooked what, over the time, w
Hi guys i need some material on multistage amplifier stability analysis. Is there any paper or guide in analyzing the stability for multistage rf power amp. thanks danesh
The power amplifier gain is part of the RF System analysis of the entire transmitter chain. The gain and loss of each transmitter stage should be distributed from the modulator up to the antenna. The gain of the power amplifier is limited by different factors, as stability, number of internal stages, (...)
I have the problem when design RF 50W & 200Mhz power amplifier, because i knew some opamp can work at high frequency so i wonder i can use opamp (now i use AD8024) for power amplifier or using transistors (an9024), could anyone help me solve that problem?
hello all i have Input and output impedance for high power transistor. (zin =real +img) how can i know if it is stabillity at this point. best regards eladg HF-amplifier? Possibly not, you need more information as S21 and S12 (gain and loss in each direction) above your know S11 and S21 (Zin, Zout) and in wide ran
If I understand you right there is only a digital controlled oscillator which drive a PA with digital amplitude control. Every other thing is digital! That is the analog/digital interface for TX. How about the RX? Channel filtering in the digital domain? Or direct RF sampling? Sorry there is not a single reference. Most of the techniques above a
Hi, I need to build a project for 10MHz oscillator (Sine Wave) and output amplifier @ about 30 to 40 Volts and 30 Watts. Can any one help me for the schematic or some site for reference guidelines. Will be greatful for.
hi all, please assist me, i want design rf amp following this spec; f=5.8ghz gain=>/=20dB I/O r.loss <-10 modulation =FSK class = ? matching = stub board = FR4 microstrip software = ADS im stuck now, where should i start?
Thank you for reply~! I use cadence RF Spectre, and PA is class AB type. I checked bias point, and linearity. For large signal, should I check others except K-factor?
Hey, I have to design a power amplifier in 130 nm technology witht he following specs power Output: > 23dBm (at PA output) Total power Consumption: < 0.5W @ 16dBm CW output power RF Input Signal @ 2.45GHz : 1Vp-p sinusoid if single ended -- differential or single ended 1.414Vp-p if differential (...)
I guess when we using spectometer, we can just check the spectrum when device is powered on and powered off, then find out if oscillation is present. As i have no decent signal analyzer, i use another approach: I make a simple probe with schottky diode, one pin grounded and other pin connected to OpAmp. Next, i put
there are two kinds of unstability:(1)the rf unstability(2)the feed DC power unstability: the resistor in the drain only conquer the feed DC unstability,but not RF unstability,try to add a resistor in the rf chain
Just wanted to ask if it's possible to stabilize an amplifier by placing a shunt resistor at the output of the amplifier. I notice that all the RF power will be shunted to ground if I place the resistor there. Adding a series inductor choke to the resistor didn't help at all, the S21 is still negligible. So is it possible?
Hi I'm looking for some help with simulating a mosfet rf power amp with either Agilent ADS or Microwave Office. I'm an absolute beginner and just can't find enough information about how to tackle exactly this task. What I want is to simulate the design I already have to see things like output power depending on input power and gate (...)
Hi, I have a simple question about the input matching of RF amplifier. If the amplifier has medium gain (about 15 dB), but bad input matching (about -3 dB), what is the impact of it to the whole RF system? Since about half of the power is reflected back to the input path, does the bad input matching increase the RF coupling, and (...)
Hi Draytek You can use either one, series or parallel resistor in input or output. The excellent explanation is given in Rowan Gilmore, Les Besser – Practical RF Circuit Design for Modern Wireless Systems Volume II - Active Circuits and Systems, Artech House, 2003 More details on, so called "device modification", which also explains
MatLAB is not a RF simulator.If you're keen to build up a real LNA, use professional simulators such as ADS, MWOffice etc.
I have got a transmitter schematic in which the carrier frequency producing part is something like this: Carrier Oscillator->Frequency Divider->RF Driver->Transformer->power MOSFET amplifier I do not understand the purpose of RF driver in the circuit...please help
First thing to do is increase C2 to 1000uF. If the power supply does not have a very low source impedance, it might help to increase C3 as well. If there is any problem with High frequency (RF) stability, it may help to connect a small capacitor (47pF to 100pF) between the collector and base of T1. C1 can be reduced to
Hi, I am designing PWM based integrated DC-DC converter operating at 300MHz clock frequency. I need to do the stability analysis of whole circuit inorder to check whether the whole feeback system is stable or not. What kind of simulations i should do for that in cadence spectre RF?. What kind of error amplifier will be suitable for this kind of
Hi everyone, I'm a newbie at RF design. Currently i'm doing a Receiver design @900MHz How do i know if i have maxed out my LNA performance in terms of gain? I know there is a balance between NF , Gain and IP3 performance. I am using BFS505 by philips with Gum of 17dB, with 50ohm matching at input and output I am achieving bout 14B gain. I h
The main reasons of low impedance bias circuit is to prevent RF to go into DC power supply, and to improve linearity and stability of the amplifier. Low impedance improve the linearity of the final stage of the bias circuit (reducing the generated distortions), and also low impedance minimize the generated noise by the bias circuit. I don't (...)