All Questions
Tagged with impedance-matching antenna
124
questions
2
votes
1
answer
31
views
Unusual chip antenna feed impedance matching
I'm designing a PCB with a RFANT3216120A1T ceramic SMD chip Bluetooth antenna.
The part is somewhat poorly documented and does not state the antenna impedance. The datasheet shows a test board with an ...
- 888
1
vote
1
answer
57
views
Maximizing magnitude of fields created by an antenna
I have a small loop antenna (\$C\$ = circumference<< \$\lambda\$ ). I am interested in the fields created by this loop at a distance \$D\$ along the z axis also small compared to \$\lambda\$.
I ...
- 395
2
votes
1
answer
50
views
Single stub matching of loop antenna at 4.2 GHz
I am trying to match a loop antenna using the single stub matching technique.
Operation frequency: 4.2 GHz
Vacuum wavelength: 7.2 cm
Cable:
Impedance: 50 Ω
Velocity factor: 0.66
The antenna impedance ...
- 395
0
votes
1
answer
32
views
Correct connection of a Wi-Fi board having both printed antennas and U.FL sockets
An RF part of a dual antenna Wi-Fi module from Aliexpress.
We can see coax sockets connected in parallel to printed antennas. Two external antennas and corresponding pigtails are part of the package.
...
- 13
2
votes
1
answer
112
views
What is the purpose of a shunt element in a balun?
I'm working on a balun for a differential front-end receiver and see that they quite often use a shunt element (inductor) across the differential pair.
From what I could gather is that when you insert ...
- 175
0
votes
0
answers
79
views
Chip antenna matching of a custom board equipped with a STM32WB55
I am planning on designing a custom board using a STM32WB55. I have followed the "How to develop RF hardware using STM32WB microcontrollers" (AN5165) Figure 9 design for the RF part, which ...
- 65
0
votes
2
answers
172
views
Why don't people always use 50 ohm resistors when matching impedances?
Impedance matching when designing the RF receiver circuit and antenna design takes a lot of time and effort for VNA. People often use capacitors and inductors to match the impedance of the antenna ...
3
votes
1
answer
99
views
Which antenna trace design is better?
I need to design an antenna trace (WiFi and Bluetooth) that connects an ESP32-S3 chip to an IPEX connector with an impedance matching circuit.
I have some constraints that I need to work around:
...
- 169
1
vote
1
answer
80
views
Where do I place my matching network for an antenna?
Let's say I have a microcontroller with an antenna output. The characteristic impedance of the pin for the antenna output is x+jy. I want to then connect it to a 50-ohm antenna.
This is the part that ...
- 2,391
1
vote
1
answer
43
views
How can I calculate filter parameters between RF switch and antenna?
In the schematics en.MB1389-WL55JC-highband-E02_Schematic,
there's a Pi filter following the RF switch before it links to the SMA connector for the antenna.
Upon calculation, I found that the cutoff ...
- 185
1
vote
1
answer
64
views
External circuit to increase the series capacitance of a resonant circuit
I am working with a long-range reader and antenna coil for a low frequency (135 kHz) RFID application (please see the basic representation below.) The reader features some unknown source impedance, as ...
- 21
2
votes
2
answers
232
views
75 ohm cable in an otherwise 50 ohm antenna system: Can I impedance match it?
I have an marine radio antenna installation as shown in the diagram. Can I place baluns (or similar devices) at either end of the 75 Ω cable to solve the impedance mismatch problem?
Background
In ...
- 21
0
votes
2
answers
102
views
Antenna tuning and L/C matching
I see there are already a few questions asked wether it is better to physcally tune the antenna for said frequency and impedance or use a matching network. It seems the conscenus is often the physical ...
- 667
0
votes
3
answers
239
views
How best to match and ground antenna?
An example of RF AM modulation:
https://www.ee-diary.com/2021/12/am-modulator-using-bjt-transistor.html
It is clear that the output is on point C4 and the circuit has a RF function, so I need an ...
user321220
0
votes
2
answers
157
views
Whats the point of the feedhorn on a dish antenna, why cant the dish just have a matching network attached to the dish directly?
Apologies if any thing i have said is incorrect. But, in the context of antennas, an unmatched feedpoint often leads to reflections, impacting both transmission and reception. It appears that if the ...
- 667