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Questions tagged [balun]

The tag has no usage guidance.

4
votes
2answers
1k views

Voltage Balun 1:1

somewhere I have seen that it is possible to build a Balun by using a transformer in the following way: The explanation I have found is that the fact that the ground is only at the primary coil will ...
0
votes
1answer
34 views

BNC cameras over CAT5 to powerline adapters then to DVR? [closed]

My apologies if this has been asked before. I have four BNC cameras connected to video baluns then connected to CAT5. Each CAT5 cable from the cameras meet in a junction box and then the video ...
2
votes
1answer
55 views

gilbert cell mixer implementation and balun

1) How do I interface LC balun with mixer using differential current RF+ and RF- input signals ? 2) How should I deal with the load impedance (RL) for LO+ and LO- which is almost infinite because it ...
0
votes
1answer
43 views

Patch antennas: explanation of examples

I am studying patch antennas for mobile communication (technology.) I have found some examples of them but without explanation. Maybe can someone explain to me the difference of examples from this ...
2
votes
1answer
154 views

Impedance matching for push-pull RF amplifier

I am working on the output matching network of a commercial push-pull class AB amplifier based on LDMOS BLF188. The output matching network consists of a 1:4 transformer and a Toroid with 8 turns The ...
2
votes
1answer
154 views

How to measure a 100 ohm differential signal on a spectrum analyzer?

I have a pair of 1.5V PCML differential signals coming out of an Altera Cyclone V GX FPGA, terminated on the FPGA in 100 ohms with common mode voltage = 0.65V (also provided on the chip). I need to ...
1
vote
1answer
114 views

Choosing toroid for FM dipole choke

After several failed attempts to buy simple rabbit ears for FM tuner I decided to make my own. Now, I have zero knowledge in RF circuits. While finding the formulas for pole length wasn't hard, I ...
0
votes
1answer
116 views

Inside of 2.4 GHz Dipole Antenna

I bought the following dipole antenna: Now I want to add some extra simple reflector and directors next to this dipole to construct a Yagi-Uda antenna. For this aim, I need to know where is its ...
0
votes
1answer
326 views

Feeding a PCB dipole with single ended RF signal

As suggested how do you feed a Dipole antenna with single ended RF IC. I found tons of examples single antenna Line feeding a differential RF port on IC but not other way round. What I want to do is ...
2
votes
0answers
157 views

Different balun configurations

I am looking for a balun to be used as a single-ended to differential converter, 1:2 impedance ratio, including range 1.5-2.5GHz, SMT and phase balance as good as possible (and return loss). Center ...
1
vote
3answers
263 views

Confusion with understanding output impedance on datasheet

I'm a little confused with a DAC datasheet and its output impedance spec. It says in the table that is has an output internal impedance of 100 ohms but then I look at the circuit application and it ...
2
votes
1answer
532 views

Balun single-ended 50 Ohm to LVDS 100 ohm conversion

I have an LVDS differential 100OHM signal which I want to convert to a single-ended 50 OHM signal. I want to use a BALUN for this conversion. What kind of BALUN should I use here? Some BALUNs have 1:...
0
votes
0answers
52 views

Feeding an antenna with a YIG oscillator

Assume I have a YIG tuned oscillator (2-10GHZ), output power 10-20mW, and an ultra wideband antenna corresponding to this range. Is there a problem with feeding the antenna directly with the ...
1
vote
0answers
132 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 ...
3
votes
1answer
225 views

Balun for impedance matching?

I would like to match the output impedance of amplifier IC (1.5 + j1.7) with an antenna of impedance (50 or 75 Ohms) at around 950 MHz. I thought of using a balun so that I could avoid the inductor ...
3
votes
2answers
2k views

sx1276 Understanding matching network

I want to use the sx1276 LORA ic as a node that can transmit and receive at 868MHz. In order to use that band of frequency one has to use Higher frequency rf pins of the chip (rfo_hf and rfi_hf). The ...
0
votes
1answer
853 views

How does a transmission line/Guanella transformer maintain Balun action at high frequencies?

A 1:1 Current or Guanella Balun is formed by winding a transmission line around a core and is used at RF frequencies as a broadband Balun. Here is an example of a terrifically broadband balun rated ...
2
votes
4answers
383 views

balun, and balun circuitry

As I understand it a balun is something that converts a line with a signal into 2 lines with mirrored signal to reject the noise like showed in this picture : I am trying to understand the balun of ...
3
votes
1answer
344 views

How to properly use a Balun?

I am again involved an RF design and I am unsure on how to connect up the Balun, minicircuits application note suggests that it is dependant on the polarity/phase of the input signals (which makes ...
1
vote
0answers
145 views

Procedure for cc430 rf tuning with chip antenna

I have designed the 433MHz RF PCB with CC430F5137 with ceramic 50 Ohm chip antenna from Johanson Technology. I have also used Balun from Johanson Technology to match the CC430 and 50Ohm Antenna. I ...
1
vote
0answers
88 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 ...
4
votes
1answer
278 views

Balun Polarity Importance

Hello I am picking up a project from someone else who has a built a dipole that is connected to a 1:1 transformer with the intention of using it as a current balun. I have noticed that from documents ...
1
vote
1answer
138 views

Antenna and balun for MRF49XA

I am trying to do a project that involves proximity detection. I need a few devices omnidirectionally detecting each other at short distance (under 20 feet). It seemed to me that sub-1Ghz RF is the ...
3
votes
2answers
289 views

Do I need coupling capacitors with this balun?

I'm connecting an antenna to Atmel's SAMR21 microcontroller and the datasheet provides this guidance: I've found 2450BL15B100E, an SMD balun, but I'm not sure if it actually contains a transformer, ...
1
vote
1answer
157 views

What is a coaxial balun and what is its construction?

I don't quite understand what a coaxial balun is. Is it a regular balun or is its wiring is made up of coax? Also, I need to convert 75 ohms unbalanced to 50 ohms balances impedance using a "...
1
vote
2answers
266 views

Transfomation of impedance using a balun

I need to convert 75 ohms balanced impedance to 50 ohms unbalanced impedance using a balun. How do I do that? I am new to this and don't really understand the concept of a:1 voltage and current baluns....
4
votes
1answer
2k views

Is this layout good? (RF - 2.45 GHz)

I finished laying out HACK, my first RF (2.45 GHz) layout. The sensitive part is the connection between the IC (Atmel SAM R21G18A), the balun (Johanson 2450BM15A0015), and the PCB antenna (copied from ...
3
votes
2answers
379 views

Role of “HDMI Baluns”?

I understand that an HDMI cable contains essentially 4 shielded twisted pairs, along with additional control lines. Each of the twisted pairs is specified, to my understanding, to be a balanced ...
11
votes
1answer
2k views

Balun/matching network question

I am having problem to verify what an app note (AN068) explains to calculate Balun values. I would appreciate if someone could tell me what/where am I doing wrong? The summary of the RF part: Blue ...