Questions tagged [antenna]

Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g. TV or radio) waves. -Wikipedia

Filter by
Sorted by
Tagged with
0
votes
0answers
19 views

Side lobe level of an aperture antenna

There is a electric field in the far zone of the rectangular aperture antenna as shown below. Antenna lies along the xy plane. $$E_{\theta}=\dfrac{jke^{-jkr}}{4\pi r}\dfrac{sin(0.5\lambda k sin\theta ...
0
votes
2answers
78 views

Hidden wire detector using BJT transistors

I made a hidden wire detector from this tutorial. It works, but I'm not quite understand why. Here is the circuit: I used 2SC1815 transistors and the value of R ...
0
votes
1answer
38 views

Change antenna so bluetooth beacon works in all directions equally well?

I am looking at using a long range bluetooth LE beacon on a project. The beacon comes with a SMA interface whip antenna that has the following radiation characteristics. It is over my head to ...
1
vote
2answers
99 views

My oscilloscope tells me I vibrate at 60Hz. How?

As I live in North America, my initial hypothesis is that I'm picking the 60Hz from my house's power line. But, to my understanding, my body can't be a 60Hz antenna (1/4 wave antenna length for 60Hz ...
0
votes
1answer
29 views

Does signal strength increment mean an increment on data speed?

For a WLAN antenna, if the signal strength is increased, can I expect higher SNR, lower bit error rate(BER) and higher data speed?
-1
votes
0answers
19 views

Aperture antennas

Is uniform aperture distribution physically realizable?why?
0
votes
2answers
48 views

Does foam have the ability to broaden the bandwidth of an antenna?

In some designs of aperture coupled patch antennas, a foam is used between the ground plane and the patch substrate. What would be main logic using it there? The reason of using it may be that when ...
0
votes
1answer
32 views

How to interpret the S-parameters of this result?

I'm designing an FSS in CST MWS that should be providing maximum reflection for the band (12 to 15)GHz and hence minimum transmission to this band. I've got the results has shown here. How do I find ...
0
votes
0answers
12 views

NFC 13.56MHz RF - Use inductor in place of pcb trace made antenna

I need to make a NFC antenna on NFC tranceiver->LC filter->matching circuit->antenna. Inductance shows to be 1.5uH on an online calculator of nfc antennas. Can I simply just place a good inductor of ...
-1
votes
1answer
38 views

How far distance a 14 dBi 5.8 GHz panel antenna can reach?

I wonder what’d be maximum distance it can reach if we consider it’s line of sight and propagation losses are minimum.
1
vote
0answers
26 views

Magnetic monopoles and magnetic field lines [closed]

in all my physics courses I have been told that magnetic field lines are absolutely closed lines. It is well explained in this wikipedia page, which states: A magnetic field has no sources or sinks ...
-2
votes
0answers
44 views

what would the world look like if we could see the lower frequency EM spectrum? [closed]

hypothetical question because curious: what would the world look like if we could see the lower frequency EM spectrum like radio and microwave radiation? Also are there any photos of the world and ...
0
votes
0answers
11 views

Does phased array antenna beam rotates 360 degrees?

I wonder what happens when the beam shifted. I mean, is it being blinded for a while at first direction (i.e 0 degree) when it goes to second direction (i.e 45 degree)? Or it complete the whole cycle ...
0
votes
1answer
27 views

phased array beam width spread as beam scans off boresite

What is the approximate phased array beam width spread as beam scans off bore site? Assume nominal scan space of 120 deg Azimuth by 90 deg Elevation, ie +/- 60 by +/- 45. Array elements are all ...
0
votes
1answer
21 views

What is the difference between 7 dBi and 10 dBi WiFi router antenna for 5.8 GHz?

5.8 GHz known as short range but higher speed for WLAN comm such as for WiFi routers. What would be advantages of using 10 dBi router antenna instead of 7 dBi at 5.8 GHz? Longer distance?
0
votes
1answer
22 views

Couplers and dividers as baluns

Can every divider and coupler that provides 3dB amplitude divison and 180 degrees phase difference be used as balun? Rat race coupler and lange coupler provide the two conditions mentioned above. ...
0
votes
2answers
25 views

A question about antenna gain and signal property

I have an antenna with a somewhat constant gain "X dBi (theta, phi)" in the frequency range of interest. With this antenna we receive a radio signal with an amplitude of "Y Volt (t)". The signal is ...
0
votes
0answers
33 views

Reduce power of walkie talkie [closed]

I have Baofeng uv-5r walkie-talkie. I know how to reduce power of this station to 1 watt using the menu. But how can I reduce its power to a lower value? For example, up to 0.5 Watts? I don't want ...
0
votes
2answers
52 views

Is MIMO equivalent to link aggregation?

Is MIMO the wireless version of link aggregation in wired networks? I'm not asking if MIMO is a similar link aggregation protocol like LACP or PAgP. What I'm asking is, if it is the same concept as ...
-1
votes
0answers
21 views

ESP8266 external antenna design

I have created an board with external antenna and used ESP-12, reference here. The problem is that I can't figure out why I am not able to get any signal at all through my external antenna. The ...
-1
votes
1answer
29 views

Impedance Matching of an Antenna

I am reading about antenna design and have a few questions which I could not get clarified. I read about "Stubs". I got to know that Stubs are used for impedance matching of an Antenna either by ...
0
votes
1answer
29 views

why base stations have 2 receiving antenna and only one transmitter?

I read that a base station is divided up into sectors to accommodate multiple service providers on a single tower. why each sector has two receiving antennas and only one transmitting antenna, As we ...
0
votes
0answers
18 views

Bluetooth Broadcasting (BlueNRG-2)

I have a few questions regarding the use of the BlueNRG-2 device I am building a system where I have to send small data packets (10 bytes) from 1 unit to 10+ units. I am aware that you can only have ...
0
votes
0answers
8 views

Dimension and beamdwidth of a paraboloidal antenna

I was reading the characteristics of the radar altimeter of the HY-2A satellite, and the antenna is described as "a paraboloidal reflector" with a dimension of 1.4 meters. Is this dimension: The ...
-1
votes
0answers
42 views

Quadriga Open software [closed]

There is a driving course tutorial in Quadriga Software. I would like to use the same tutorial with amendments to simulate a scenario with a single transmitter and eight other receivers. The main ...
1
vote
1answer
25 views

How to use two antennas with a single Bluetooth module? (BLE repeater)

I am working on a project that uses small Bluetooth low energy (BLE) beacons to track important items. However, we have run into a situation where one location will store these items underground in a ...
0
votes
1answer
19 views

Array antenna gain expectation

Should I expect 28 dBi gain if I design properly 2x2 microstrip patch antenna array in which an element has 7 dBi gain? Or expectations should be 10-11 dBi?
2
votes
4answers
2k views

Television antenna comparison for signal reception

I bought two antennas for over-the-air TV reception. They are the "Mohu Sky 60" and the "Channelmaster CM2020." I was wondering which is likely to get the strongest signal before amplification when ...
0
votes
0answers
21 views

Verifying an existing Micro chip RF component range with my calculations

I'm trying to understand how the microchip RN4871 chip range is calculated. I know the chip Antenna used in this module. According to its datasheet, RN4871 has a range of 10m. So my calculations ...
0
votes
3answers
83 views

Different antenna lengths for different frequencies?

I just want to understand a few things which I couldn't get clarity from a lot of websites searched through google as I could see differing information. My questions : How does a single FM antenna ...
0
votes
0answers
15 views

Antenna Theory and Electron Paramagnetic Resonance

Hi I am trying to understand why and how Antenna Theory works as it does. I can only link Antenna Theory to Electron Paramagnetic Resonance @ 2.8Ghz but I do not know how I can link the resonant ...
1
vote
1answer
40 views

Electric current injected to ionized gas around laser beam or electron beam to make miles high ham radio antenna

I found there was a technology which uses air plasma around electron beam or laser beam and it is about injecting current in to this plasma to make far away bombs explode or damage car electronic, or ...
0
votes
0answers
36 views

Antenna range calculation

I'm trying to build a microstrip antenna for my BLE module to increase its range. I'm more of a hardware Design and firmware guy and the last time I designed an antenna was in college back in 2015. ...
5
votes
4answers
613 views

Why should a receiving antenna be impedance matched to 50 ohm instead of a lower impedance?

I'm in the process of getting to grips with RF design and am having some trouble understanding why we should always match antennas to \$50\Omega\$. I understand from the maximum power transfer ...
0
votes
0answers
26 views

Troubleshooting NOAA double cross antenna

I've been trying to recive NOAA automatic picture transmission (APT) pictures for a year now. I never got a picture with V-dipole, so I decided to build a double cross antenna. I used 75 ohm coax ...
0
votes
0answers
12 views

How to make Broadband Aperture Coupled fed MSPA

When I design broadband(i.e 1.6 GHz bandwidth) patch antenna generally used aperture coupled for higher bands such as Ku band. However, with the same design rules, if I tryna make it at lower ...
0
votes
1answer
54 views

Controlling a digital switch using Python through USB

I have an RF digital switch that takes two digital inputs (AB) in order to decide from which antenna port to take the input. Is their a simple way to use Python to send the AB values through the USB ...
0
votes
1answer
20 views

How to adjust the feed line of 3x3 patch array

I stuck with some questions about 3x3 patch array. It's said that patch antenna frequently is 200 Ohm. Is it always? Ain't that change with antenna design parameters such as length? Do I have to ...
0
votes
0answers
20 views

Extending a 433 MHz antenna connected to a PCB

I want to convert a standard 433 MHz temperature sensor so I can use it to monitor the pool temperature. I can enclose the PCB and the batteries in a waterproof container. The pool is salt water ...
0
votes
1answer
42 views

PCB Antenna Tuning

I am trying to tune an antenna as seen above, using this wonderful Smith Chart Tool. It needs to match 35 + 10j characteristic impedance. I have found a tool like the Microstrip Impedance Calculator ...
0
votes
3answers
36 views

Spherical waves in far field region

in my antennas book (I do not put its reference because it is not in english) it is written that, at high distance from the source, the electromagnetic field radiated by it is a spherical wave. This ...
1
vote
2answers
32 views

What does 'isolation' mean in a radar antenna system spec text? How to measure it?

It says "85 dB minimum at 18 inch centerline-to-centerline over the OFR". What does it mean? How do I measure that isolation value? in this Text
1
vote
1answer
49 views

Is there an easy way to interface a receiving 457kHz ferrite rod antenna with a microcontroller (BeagleBone Black)?

I have a (actually two crisscrossed) 457kHz ferrite rod antenna from the internals of an avalanche beacon where 196uH <= L < 204uH and C = 560pF. I need to be able to evaluate the data from the ...
4
votes
6answers
2k views

How does a mobile phone send signals? [closed]

I wonder how a mobile phone (handset) sends signals to the Base Transceiver Station (BTS). The BTS is obviously quite large and, thus, possesses much more power than a phone does. So, how is a phone ...
0
votes
0answers
10 views

How to reduce side lobe level occurred because of the mutual coupling in patch antenna array?

From what I think, mutual coupling in patch antenna array causes higher side lobe level. Am I thinking right? Would mutual coupling reduction mean side lobe level reduction as well? If so, can I ...
0
votes
1answer
30 views

A Circular-Polarization Reconfigurable Meng-Shaped Patch Antenna

How are the pin diodes in this antenna with chinese character actually related to circular polarization ? What are dimensions D and Fv in the paper?
0
votes
1answer
37 views

Does using an antenna extension cable violate FCC cert?

I have a question about FCC part 15 certs. Using the Particle Cellular B series SoM, they have a "Grant of equipment authorization" to use the module as an end device. Link to the module docs below. ...
0
votes
0answers
15 views

How do i set up an offset antenna?

How do i set up an offset antenna? I have two offset antennas. 1 for receiving and the other one for transmitting, they are at the same altitude. I don't know how to set up the angle because the beam ...
0
votes
1answer
26 views

How to calculate component value of a matching network

You can already expect my knowledge level In antenna designing (newbie). This may be or may not be a stupid question. The reason is I don't know about this very much. Iam designing a PCB for ESP32 ...
0
votes
0answers
12 views

E-plane and H-plane pattern of an antenna

When I want to analyze E-plane, I look at phi=0 whereas to analyze H-plane, looking at phi=90. However I get minimum gain at phi=0 but maximum at phi=45. How can I call this phi=45 degree as a plane? ...

1
2 3 4 5
26