Questions tagged [matching]

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3
votes
1answer
54 views

Should Ethernet MDI Pairs all be Length Matched (Inter-Pair) before going into magnetics?

I've been trying to find information for the above question and I can't seem to find anything. I have 1000 BASE-T lines coming from an Ethernet cable to a PCB mounted connector. I'm pretty much ...
-1
votes
1answer
43 views

Level Matching Circuit

Somebody know what do this circuit exactly or how it works ? Where VDD = 5V (MCU) and VDD_1V8 = 1V8 It is a recommended circuit to use uart communication when the voltage level are not the same, I ...
0
votes
1answer
65 views

Differential pairs; length matching between pairs

I'm currently busy routing a high speed design containing MIPI signals @ 2,5Gbit / lane to a connector on an 8 layer board. As MIPI also contains a clock pair, it is advisable to match the length ...
0
votes
1answer
28 views

driving a medium power darlington transistor with the output of a 555 timer

Question: What is the limitation on the output of the 555 timer with respect to the requirements of the input of the BDW42G? Can the 555 provide enough current at 5 volts to trigger (sufficiently) ...
0
votes
0answers
51 views

Question about 50ohm impedance matching circuit

I am implementing rf energy harvesting circuit. The rectenna is working at 915MHz and the impedance is 50Ω. I think L-matching may be the easiest. However, I don't have the vector network analyzer. Is ...
3
votes
5answers
577 views

What circuit can be used to match input to output voltage by using an opamp?

What is the simple way matching an input voltage range to a desired output range. To be more specific with an example: If I want to convert/match 0V-5V input range to 7V-15V output range linearly, is ...
0
votes
1answer
63 views

Impedance Matching Network with tracks+connectors in between (practice)

I've been struggling on how to design (and develop in practice) an impedance matching network with some traces/tracks/paths (whatever you wanna call it) and some connectors in between. So here is the ...
0
votes
0answers
30 views

Analogue Video Trace Matching

I'm working on an analogue audio, video and sync board for my Dreamcast. Something I've been wondering about is the tolerance for analogue video, specifically RGB, in regards to the delta for trace ...
2
votes
1answer
549 views

How does this impedance matching circuit work? How to simulate it correctly in SPICE?

I have a schematic for a current sensing circuit using a dedicated TI differential amplifier part for current sensing applications. The schematic also includes an "impedance matching" part for ...
0
votes
2answers
127 views

Narrowing a microstrip's tip

I have designed a 50 Ohm microstrip line. Following is an image of it. This is drawn in Eagle. Two layer PCB. Blue plane is the ground plane. The dimensions are: Width: 1250 micrometers Thickness: 1 ...
1
vote
2answers
336 views

Impedance matching: L-network or micro strips?

I'm trying to embed a u-blox neo6m gps module to an stm32 controlled board. I'm planning to connect the module to an SMA connector and use a 50ohm antenna. The datasheet of the neo6m states that the ...
0
votes
1answer
115 views

Receiver and transmitter with the same antenna [duplicate]

I want to build a simple transceiver (half duplex) for 433.92 MHz ASK modulation. I have found a transmitter chip and a receiver chip that I want to use. I want to use the same antenna for RX and TX ...
0
votes
1answer
188 views

What is the op-amp in this JFET-matcher circuit?

In the circuit diagram on this page, there appears to be an unspecified op-amp. Could anyone guess at a component I could use for this and/or explain why there is no specification? Background: I am ...
1
vote
0answers
138 views

Ouput impedance of a balun

I am using the CC1110 RF IC and I am having trouble when matching the differential RF output impedance with the antenna. The datasheet states that the differential impedance seen from the RF output ...
-1
votes
1answer
278 views

Voltage source and its load resistance matching

i have implemented DAC controlled DC voltage source. I'm having trouble understanding physical reasons for voltage error due to load resistance change. My circuit desing was taken from DAC ...
1
vote
0answers
19 views

Impedance matching for inductively powering / rectifier

I have two questions. If the receiver is inductively powered (by LC resonator) and needs a matching network in front of the RF-to-DC rectifier, what kind of quality factor of matching network (or Qs ...
1
vote
1answer
349 views

Matching wideband antenna with QUCS

I am trying to match a dipole antenna to a 50Ω source. Problem is that for my frequencies (VHF) the complex impedance basically circles the 50Ω point between VSWR 2 and 3 lines. Because of that ...
0
votes
0answers
125 views

Quality factor of Quarter Wave Transformer

I'm having trouble to find how to calculate the quality factor of a quarter wave transformer. I've been finding information to compute the quality factor for L circuits, PI and T circuits, and Tap ...
5
votes
2answers
1k views

Antenna Matching Network

I am trying to match a gsm antena, doing it on a pcb, first time in practice. I understand the whole process to adapt it, I've done it in simulators. However, I don't understand the need for a pi ...
1
vote
0answers
3k views

How do I convert S-parameters for impedance matching?

How do I derive the Z-parameters to calculate a matching network for a device? I'm not sure what terms to even search for as I get all sorts of information I am not familiar with. My task is to ...
2
votes
1answer
468 views

Calculating characteristic impedance of a matching line

Attached is a question asking for the characteristic impedance of a matching line. A matching line of 0.25\$\lambda\$ has at its beginning an impedance equal to: $$Z_{in}=\sqrt{Z_{c}Z_{L}}$$ if I am ...
2
votes
1answer
144 views

Resistive on-die termination

It is widely known that resistive termination (e.g. 50 Ohm to ground) is superior when noise is no concern. Specifically in the block diagrams of RFICs I see many 50 Ohm resistors to ground directly ...
0
votes
1answer
154 views

Matching radio tubes - what is widelly accepted tolerance in parameters?

When matching radio tubes, most important parameters are anode current and transconductance. Is there widely accepted tolerance in parameter variation? I have read an article where tubes are ...
0
votes
0answers
291 views

Capacitor matching by capacitance multiplier

I am developing an analog fully differential circuit that needs a tight capacitor matching to reach high performances. Because discrete capacitors are difficult (and expensive) to match for production ...
1
vote
1answer
155 views

Impedance matching high power transistor when VNA is useless

Recently I've been stuck up with the high power transistor (2-10W) at 900 MHz that needs to deliver 30 dBm of the broadband signal to the antenna. Since it works in the high power mode, it behaves ...
0
votes
1answer
59 views

Antenna microstrip feedline discrepancy?

I've been looking at some reference designs to guide my own design recently, and I noticed some possible discrepancies on one in particular. This is the reference design: http://www.ti.com/lit/ug/...
0
votes
2answers
206 views

Impedance matching with unknown filter

My question is related to impedance matching when using a function generator and oscilloscope to identify a type of passive filter, i.e. low pass, high pass, etc. If I output a function sweep from a ...
0
votes
2answers
112 views

Good inductor parameter for GHz frequency matching chosing

I want to buy inductor and capacitor for matching circuit of antenna in about 1.6GHZ. I searched the net for some inductor for ...
1
vote
0answers
89 views

Reliable antenna matching design of quadrifillar helix

I have simulated this antenna : I found its impedance, I know I have 50 ohm transmission. I decided to match these by discrete part in feed point, The match circuit is I want to ask from those who ...
0
votes
1answer
79 views

Matching an amplifier to a video transmitter

What I'd like to do is to amplify a signal coming from an analog Video Transmitter. I've created a small circuit according to the application circuit description of the "High Gain Driver Amplifier" (...
3
votes
1answer
368 views

How to make an impedance matched circuit for fabbed antenna?

Okay I have developed an antenna for a system and need to create an impedance matching circuit. The theory of conjugate matching is simple, but actually implementing it is something I can't find ...
7
votes
2answers
2k views

Transmission Line: characteristic impedance matching

The textbook explains a situation in which when you have 2 unmatched transmission lines (different characteristic impedance), you can connect a new line in between such that the input impedance would ...
1
vote
1answer
417 views

matching network design for transceiver with differential outputs

I'm trying to learn about matching networks. I have a 2.4GHz radio chip with differntial TXP/TXN outputs, and RXP/RXN input. These both share the same single ended antenna. I've been reading and I ...
6
votes
2answers
803 views

question about transistor matching circuit

I'm studying this transistor matching circuit provided initially by Bob Moog. I think I mostly understand how it works, the op amp, bjt not under test and resistors form a current source, which stays ...
5
votes
1answer
751 views

Matching transistors for discrete opamp (audio use)

I am building some GAR2520 discrete opamps that require a matched pair of BC550(CTA) NPN transistors. I built a simple emitter follower with a 15V supply, biased at about half that. I input a 1khz ...
1
vote
2answers
271 views

Matching ground references between computer and small DIY amplifier

I am teaching myself about audio amplifiers and put together a basic circuit to receive the signal from my laptop and then drive a pair of 32 ohm headphones. The small amplifier is powered by the USB ...
2
votes
3answers
105 views

Whats a good naming convention for part series and shunt components?

I have an RF receiver circuit which includes a ceramic chip antenna. Our chip antenna manufacturer "fine tunes" this antenna to the board and housing by determining the values of the Shunt and Series ...
-1
votes
1answer
186 views

Transformer characteristic for impedance matching in RF

In an rf impedance matching circuit it is assumed that transformer is ideal or large enough. I just wanted to know the quantification of "large enough" (which parameter is large with respect to what) ...
2
votes
3answers
2k views

Impedance matching routes in Eagle board

I am making my second board using Eagle CAD. I have different components with a set of different sizes. I set the minimum width for lines to be x. That way, the autorouter creates EVERY line in that ...
0
votes
2answers
1k views

Basic NFC Loop Design on PCB

I'm a college student learning the basics of NFC loop antenna design. As a starting point, I'm trying to design a PCB-based rectangular NFC loop operating at 13.56 MHz, matched to 50Ω. (NFC "...
4
votes
1answer
1k views

Matching the impedance of a filter?

Currently designing a circuit consisting of 50 Ohm rated ICs. Between two ICs (switches), I will place a BP-filter made out of discrete components (high-Q inductors and capacitors). The filter will ...
0
votes
4answers
695 views

Impedance matching for amplifier output

I needed some basic advice about impedance matching. I have an RF amplifier with 50 ohm output impedance, capable of generating 400W output power at 500kHz. I am trying to deliver this to a 12 ohm ...
5
votes
3answers
2k views

Impedance matching an RLC circuit (inductor macroscopically drawn on PCB)

Context: I am a physics grad student with basic knowledge of circuits, but impedance matching and RF domain are beyond my normal scope. My PCB is actually copper bonded to a ceramic substrate that is ...
3
votes
3answers
813 views

CC1120 and RF output pin and network

I am working on a hobby design and thinking of using the CC1120 for my RF transceiver. One thing that has me confused, however, is the matching circuitry on the RF input and output of the CC1120. I'...
8
votes
2answers
1k views

A poor man's alternative to a network analyzer for antenna matching

I'm doing a small board with a 915 MHz transceiver. A small helical antenna is used, which is located on board with a very short path (10 mm) from the IC, including balun and a matching network. There ...
2
votes
1answer
200 views

Computational complexity of current netlist matching algorithms

I understand that the problem of matching two netlists could be reduced to the graph isomorphism problem which is NP-intermediate. Apart from that what are the complexity results of some of the ...
1
vote
1answer
306 views

Impedance Matching Resistor

I'm working on a high speed ADC/DAC board. I saw some reference designs for the device, there are matching series resistors connected between output digital pins & controller. Though, resistor ...
5
votes
3answers
5k views

Custom USB Impedance question

I'm looking at making my own USB cable for a project. The primary issue I'm having is that I'm getting a lot of capacitance in my cable between D+ and D- (400ish pF) which is enough to throw off the ...
1
vote
0answers
687 views

Problem with impedance matching on DIY 4 pole 3.5mm audio splitter

I built an audio 4 connector 3.5mm splitter. The goal is to play a sound clip through a phone's mic input across a call, while recording the same sound clip on the computer. I used the TRRS ...
3
votes
1answer
485 views

Matching mosfets - linear servo amplifier (AB)

I'm replacing a bunch of burnt mosfets in a linear amplifier for a brushless motor. 3 phases Each phase: 3 pairs of totem IRFP240 / IRFP9240 in parallell. (no R in series) My main concern is ...