140 Threads found on edaboard.com: Matching Source And Load
Hi everyone this is my first post. I am a electronics noob so please be patient with me.
I don't understand the concept of impedance matching. Why would you want to increase the impedance in the source, I would think that any increase in the impedance of the source is just wasted power. Maybe my problem is I am thinking (...)
Electronic Elementary Questions :: 29.07.2009 17:06 :: faradayfan :: Replies: 4 :: Views: 1787
An impedance matching calculator. You specify the real and imaginary values for the source and load, specify the frequency of interest, and LCMatch calculates all possible two element matching networks, (LC, CL, CC, LL).
RF, Microwave, Antennas and Optics :: 17.09.2001 07:40 :: Robin Hood :: Replies: 0 :: Views: 3019
is a lumped element calculator with many topologies.
RF, Microwave, Antennas and Optics :: 16.06.2003 22:20 :: flatulent :: Replies: 1 :: Views: 1050
It depends on amplifier...
If the amplifier is a high power amplifier at RF frequencies, "optimum load impedance" should be found and matching is done with this impedance.
Or if the amplifier is low power or small signal amlifier, matching should be done with "conjugate matching technique" to obtain (...)
RF, Microwave, Antennas and Optics :: 18.06.2006 18:41 :: BigBoss :: Replies: 8 :: Views: 757
load pulling the input and the output in order to generate load circles on the Smith chart is the practical way to do this, either in the simulator or on the bench. Theoretical matching starts to depart from reality with Power amplifiers.
RF, Microwave, Antennas and Optics :: 25.07.2006 14:34 :: toonafishy :: Replies: 3 :: Views: 934
Should the Q of matching network at the PA output as large as possible?
To keep the circuit stable, the Q is generally between 1 and 3. How to choose the Q?
should I choose 3? or just 2 is enough?
RF, Microwave, Antennas and Optics :: 10.06.2007 03:26 :: zhaofeng1983 :: Replies: 7 :: Views: 1271
He is very ambiguous in what he is asking about in 2nd ed problem 3.1.
Any directions will be appreciated. I have read the chapter very properly and understand the L-match etc but cannot figure out what is he talking about.
It seems like some important point the seniors must know.
Consider two approaches to matching a purely resistive 7
Electronic Elementary Questions :: 10.06.2009 13:15 :: willdoit :: Replies: 4 :: Views: 962
Vfone is correct, google Conjugate matching.
Also, you will see that a match for optimal Gain will not be the best match
for Max Pout in general.
RF, Microwave, Antennas and Optics :: 12.01.2010 16:27 :: Element_115 :: Replies: 4 :: Views: 739
Can any one guide me how to do 2 element lumped elements matching inorder to match a source impedance of 25-j15Ω to 100-j25Ω.
frequency of signal is 60 MHz , although I just need the procedure .
RF, Microwave, Antennas and Optics :: 07.03.2010 12:03 :: mhussainshah :: Replies: 3 :: Views: 927
i want to match Z-source and Z-load impedance at 2GHz which are present in the attached file, using ADS Smith chart utility. I am confused about the behavior of this utility.
At 2 GHZ Z_load is 19.4+j*39.9 ohm. It is provided in the source and load termination (...)
RF, Microwave, Antennas and Optics :: 06.01.2012 01:56 :: adnan012 :: Replies: 0 :: Views: 838
I have input signal where capacitive part is dominated.
Do you mean a mostly capacitive source impedance?
I have input signal where capacitive part is dominated.
What demands compensation? Are you required to achieve impedance matching?
However I am getting too narrow characteristic. As result it very se
Electronic Elementary Questions :: 09.09.2012 16:40 :: FvM :: Replies: 5 :: Views: 266
You can use a directional coupler, it measures forward and reflected wave. By nature, it has a finite transmission line length and a characteristic impedance. But if it's short related to wavelength, it won't cause large changes to the impedance matching, presumed the characteristic impedance is roughly in the same range as the (...)
RF, Microwave, Antennas and Optics :: 07.07.2013 11:07 :: FvM :: Replies: 4 :: Views: 227
In general we want all power from the source to get to the load. matching means that source and load resistance should be equal (for sinusoidal signals, conjugate) to meet the best transmission condition.
Analog IC Design and Layout :: 04.08.2013 03:20 :: jiripolivka :: Replies: 5 :: Views: 307
As you said, sometimes it is intentional to merge bias/match network and this is obvious.
The bias network, if not well designd can impact on signal, so on s parameter of the LNA.
Also the layout is fundamental, of course.
But I do not really understand your problem: could you be more detailed?
Furthermore, do not expect perfect matching (...)
RF, Microwave, Antennas and Optics :: 07.06.2004 11:45 :: Mazz :: Replies: 11 :: Views: 1420
1- frequency multipliers are used as signal generation technique, permeting one to abtain and utilize the harmonics of a fundamental frequency technique, meaning if your input frquency is "f" you can get 2xf or 3xf ...
2- one of the approches that is been used for analog divider and multiplier is gilbert cell multiplier, there is a
RF, Microwave, Antennas and Optics :: 02.03.2005 17:32 :: bouchy :: Replies: 1 :: Views: 752
does anyone out there know anything about matching Networks.
I want to Design matching networks to operate at a frequency of 750MHz, and a bandwidth of 10MHz to match a load of 75W to a source of 50W.
where should i start.
Electronic Elementary Questions :: 07.04.2006 04:38 :: BD :: Replies: 2 :: Views: 501
I think there are a lot of things confused in your question. I am not sure that R = SQRT(Rsource*Rtline) is used for any matching?!
It is probably
for quarterwavelength transmission line transformer matching between source (...)
RF, Microwave, Antennas and Optics :: 12.06.2006 14:56 :: flyhigh :: Replies: 2 :: Views: 810
due to high gain and reverse gain S12 of the transistor , at low frequencies the transistor become unstable this make the AMP OSCILLATE for some load and source terminattion
if the amp is unstable some times the input impednace become negative , and S11 become larger than one
check gonzalez book or (...)
RF, Microwave, Antennas and Optics :: 09.07.2006 09:37 :: khouly :: Replies: 7 :: Views: 1022
As a start, instead of dealing with the complexity of a microphone feeding a transformer which feeds an amp, why not say that any complex network can be modeled with a voltage source and a series resistance?
If you say this, then you could analyze a simple voltage divider circuit, which is what power transfer is after all.
Next, if you want a
Electronic Elementary Questions :: 28.09.2006 19:45 :: Euler's Identity :: Replies: 2 :: Views: 913
I have a CMOS input amplifier in an schematic design in ADS, and excite it with a 1-tone power source of 50ohm Rs, at 900MHz.
Could you suggest an easy way to get a matching network in ADS ?
I know how to use the Smith chart utility included in ADS where you give your input and load impedances (...)
RF, Microwave, Antennas and Optics :: 27.10.2006 10:32 :: STOIKOV :: Replies: 4 :: Views: 1218
It is called impedance matching transformer or sound output transformer... match the transformer output impedance to the impedance of speaker..
Analog Circuit Design :: 01.03.2007 19:28 :: wisepie :: Replies: 3 :: Views: 840
in the LNA , all u want is a very low noise performance , and this hold that u must match the input from minimum noise which is not the matching for bet S11 , S11 will be -20 or -15 if ur matching for max gain
i think it is normal , check ur gain , and noise figure
RF, Microwave, Antennas and Optics :: 04.03.2007 01:59 :: khouly :: Replies: 12 :: Views: 992
How to design input matching of SA636 for 374MHZ (50 ohm) RF input signal?
How to calculate L,C values?
RF, Microwave, Antennas and Optics :: 28.06.2008 15:10 :: 7rots51 :: Replies: 9 :: Views: 1299
There are the two separate matching cases: optimal noise matching and conjugate matching. The first one in used to match LNA input to preceding circuit. It may be filter, antenna, transmission line or something else. This kind of matching provides the lowest noise figure, but may introduce some mismatch (...)
Electronic Elementary Questions :: 21.07.2008 23:47 :: RF-OM :: Replies: 4 :: Views: 1111
how does the Quarterwave(lambda/4) transmission line acts as a matching transformer between source and load impedance?
why not half wave transmission line???????
thanking in advance
RF, Microwave, Antennas and Optics :: 18.08.2008 07:43 :: chandregowda :: Replies: 1 :: Views: 559
I am designing an amplifier at 2 GHz. while designing the matching network, this is how I understand it:
for i/p: Zo has to be transformed to Zs conjugate so plot Zs conjugate on smith chart and move from center of smith chart to tht point.
for o/p: ZL conjugate has to be transformed to Zo so plot ZL conjugate and move (...)
Electromagnetic Design and Simulation :: 06.06.2009 10:03 :: mw_rookie :: Replies: 6 :: Views: 2881
I am having the following problem on my class-e amplifier design.
My S-Parameter analysis shows S11=1.004<-158.5 and S22<766.5u<137.4.
If I am correct that's Zin= -0.1034-9.49276i and Zout=49.94358+0.05182i proving that my output is matched to my 50Ω load.
The problem is that I can't figure out how to match my input to a 50Ω (...)
RF, Microwave, Antennas and Optics :: 21.06.2009 02:57 :: cmos_vlsi :: Replies: 3 :: Views: 827
Using a transformer means you get inductive coupling, and not capacitive coupling.
Using just capacitors, without any inductance, you lose the interstage impedance matching. That means you are losing power.
So, there is a possibility to eliminate the transformer, with an LC matching network.
RF, Microwave, Antennas and Optics :: 28.12.2009 04:32 :: vfone :: Replies: 4 :: Views: 2186
High speed differential pairs always means impedance matching (e.g. 100 ohm) as well, so there is effectively no problem with trace capacitances.
Differential pairs at low speed can mean a lot of different things. At least, it usually involve improved common mode rejection, but trace impedances, source and load (...)
PCB Routing Schematic Layout software and Simulation :: 12.02.2010 18:12 :: FvM :: Replies: 12 :: Views: 1912
The amplifier has 400 overall gain with about 150 MHz bandwidth. It's very easy to get oscillations by unwanted coupling between input and
output or through power supply. Apparently, you didn't use a suitable "RF" circuit layout. A continuous ground plane and additional supply
decoupling by ferrite beads is suggested, also correctly (...)
Analog Circuit Design :: 28.05.2010 01:49 :: FvM :: Replies: 6 :: Views: 1209
Is their any simulator or software which can help me to do this?
Yes. One tool which can do this is ZMatch from Nuhertz:
Zmatch, Impdedance matching Network Synthesis and Analysis Software for Electrical Engineers
RF, Microwave, Antennas and Optics :: 03.10.2010 13:49 :: volker_muehlhaus :: Replies: 10 :: Views: 1741
Hi all. I know this will be a stupid question but I'm really confused. Attached is a picture of my amplifier design.
Transistor used is ATF 36077 and topology is cascaded, reactively terminated amplifier.
The microstrip transmission lines are supposed to be for matching purposes however I don't know what value of impedance to put on the transmi
RF, Microwave, Antennas and Optics :: 10.01.2011 04:23 :: rcgalicha :: Replies: 2 :: Views: 647
There are basically two kinds of transmission line impedance matching, source side (series termination) and load side (parallel termination). As you can easily see, source series termination is preferable, because it doesn't introduce additional power dissipation.
My question is How to reduce or avoid (...)
Analog Circuit Design :: 23.05.2011 01:40 :: FvM :: Replies: 7 :: Views: 3442
What will happen if I don’t place them?
This is a lowpass filter, to meet the regulations (out-of-band transmitted power).
Depending on the values, it can also be used for antenna impedance matching.
RF, Microwave, Antennas and Optics :: 27.06.2011 03:27 :: volker_muehlhaus :: Replies: 16 :: Views: 1094
As a part of understanding how to optimize matching networks in cadence I am designing a matching network to match 10 ohm load to 50 ohms source at 6Ghz. I am using simple L matching network and I know all the equations required. I come up with the required values (...)
RF, Microwave, Antennas and Optics :: 12.07.2011 14:47 :: niranjan1984 :: Replies: 2 :: Views: 501
In the first place, I would also ask for the exact receiver output configuration (whatever it is, either analog or digital signal). and then try to understand, what exactly "doesn't work"?
Common collector follower means a single transistor with emitter resistor. But it involves a voltage shift and would need a negative supply not to clip (...)
Analog Circuit Design :: 15.08.2011 17:19 :: FvM :: Replies: 11 :: Views: 2388
With loop inductance and frequency known, can you calculate expected capacitance for resonance.
This value can be needed to be adjusted depending on how you are connecting to the antenna and if it should include coupling effect from RX loop and its load.
Connecting 50 Ohm source can be done in many ways, (...)
RF, Microwave, Antennas and Optics :: 28.03.2012 08:26 :: E Kafeman :: Replies: 13 :: Views: 2185
Please explain in more detail what you are looking for.
Transmission lines, inclusing microstrip and stripline, are inherently broadband if the line impedance Zl=sqrt(L'/C') matches the input and output impedance at the end of the line. From your question, I would think that your problem is impedance matching/wrong (...)
Analog IC Design and Layout :: 22.04.2012 05:45 :: volker_muehlhaus :: Replies: 6 :: Views: 412
Re-read the conjugate matching concept, Conjugate matching between source impedance and load impedance means the maximum power should be transferred from source to load, the efficiency is 50%.
No, if correct ideal matching is transmission loss 0%.
if the (...)
RF, Microwave, Antennas and Optics :: 14.06.2012 10:03 :: E Kafeman :: Replies: 6 :: Views: 340
Why did you place a voltage divider? The filter can be implemented with 50 ohm matching as well.
RF, Microwave, Antennas and Optics :: 25.06.2012 09:18 :: FvM :: Replies: 12 :: Views: 1056
lots of controlled impedance strip lines. Prop delay must be a controlled impedance for analog broadband, otherwise, most people try to get the delay out of the chip ;) Normally snake shaped tracks are used to offer proper delay for matching bus signals.
Analog Circuit Design :: 31.07.2012 21:06 :: SunnySkyguy :: Replies: 6 :: Views: 403
thanks for the work you did.
It is a school project. I will talk to the professor about this issue. The best matching network I used gave me instability between 100MHZ and 400 MHZ, and other regions were stable. The problem I have to make sure it is stable in the entire frequency band (100 Mhz to 6 Ghz). I have used (...)
RF, Microwave, Antennas and Optics :: 12.02.2003 20:58 :: ayhz2002 :: Replies: 8 :: Views: 1234
The problem I meet is that the input R.L is bad, just as D.J mentioned, and due to the limitation of our measurement system i can not do source matching, can I still use fixed dilevered power to find the optimial load, with the absorbed input power changes much at different load?
another thing is how to (...)
RF, Microwave, Antennas and Optics :: 17.08.2004 16:11 :: dpxiao333 :: Replies: 5 :: Views: 978
Suppose we have an RF power amplifier that the manufacturer has stated that in order for the amplifier to provide max power , it has got to "see" a load characterized by some impedance vs freq.
We also know that the amplifier in NOT linear (something like class C for example). We want to use the amplfier in a narrow band system, so we try to ma
RF, Microwave, Antennas and Optics :: 12.01.2005 20:21 :: mixaloybas :: Replies: 2 :: Views: 664
For the Pi or T impedence matching network,
the two resonant L network have different Q if the
load and source impedence is different.
So, what is total Q for whole T or Pi network?
Is it the larger one?
Thanks a lot.
RF, Microwave, Antennas and Optics :: 21.02.2005 20:17 :: tony_taoyh :: Replies: 3 :: Views: 1568
Is it necessary to calculate the impedence matching in a simple step down transformer considering the line frequency ?
Will a transformer designed for 60 Hz fall out on efficiency at 50 Hz ?
How is the current rating of the transformer detirmined ? by the thickness of the wire or the number of turns ?
To make a step down from 220 to 110 on
Analog Circuit Design :: 26.05.2005 08:10 :: Lord Loh. :: Replies: 3 :: Views: 989
impedance matching commonly use in the high frequency aplifiere design.
you can use the matching for this reson
1-obtain the max of gain
2-minimum the noise
3-transfer the max power to load
4-reflection of eergy is low
and so on. you can use the RF circuit design by Ludwig in the EDA book download for (...)
Analog Circuit Design :: 31.05.2005 23:30 :: carrier :: Replies: 13 :: Views: 1512
Power supplies does not need any impedance matching. They are supposed to be as much as possible a voltage sources and thus their internal impedance should be as low as possible. If their internal impedance is high they will waste significant amount of power what is not wanted.
Another thing is matching (...)
Analog Circuit Design :: 27.07.2005 08:57 :: Borber :: Replies: 6 :: Views: 830
I just want to know the Q you mentioned is for which network. As we know for L network, the Q is fixed by the input resistance and output resistance. Since you want to match 2.3 ohm to 3.3 -j 3.94, you should include the -j3.94 to your network first, so the matching is from 2.3 to 3.3, the Q is fixed if you still want to (...)
RF, Microwave, Antennas and Optics :: 08.10.2005 01:03 :: pi331133 :: Replies: 9 :: Views: 1957
I have an LNA whose output is matched to 50Ohm over a small frequency range (LC matching). The stage following the LNA is a filter who is designed to work with 50Ohm load at input and output. Now outside of the band of interest, the LNA is not matched to 50Ohms and therefore the filter (...)
RF, Microwave, Antennas and Optics :: 24.01.2006 10:06 :: Ghost Tweaker :: Replies: 1 :: Views: 592