# Tag Info

6

This answer is based on extra information provided by the OP in the form of a photo. The claimed currents were far too low due ti a misunderstanding in how to read the meter's 10A range display. The prior answer is correct given the information provided by the OP re currents being at sub-mA levels. As such it is useful to readers seeking to understand the ...

5

This happens on a bit level of the receiver electronics. For every byte you have to receive 8 bits. At this point in communication you only decoded the signal (eg. converted the electrical power or voltage) levels to bits. You receive bits in the buffer. You are constantly filling the buffer (on a bit level), so you can check the buffer to see if you ...

4

There is information out there, but probably the best way to find out is to actually try it. Grab a small Bluetooth or Wifi device and seal it in a waterproof enclosure or bag, and submerge it to the bottom of the fish bowl under water. See what happens. This should provide more valuable insights than the simple theoretical RF attenuation of water per ...

3

No, they are securely fixed (soldered) to the circuit boards. If you think you have heard the term "float" with reference to a chip, then you are probably hearing about "floating point arithmetic" which is the process used inside the chip to solve the mathematical equations and calculations we want.

3

Unfortunately, you are in a bit of a bind. You need a combination of things to successfully achieve your experiment, and I doubt you be able to achieve it using a commercial microwave oven. First, you need to build a faraday cage around the section you want to not be exposed to microwaves. Faraday cages (https://en.wikipedia.org/wiki/Faraday_cage) provide ...

3

I am not sure if this will help, but when I have used any plastic in antenna designs, or RF power amplifiers, I would put them in a microwave oven and see if they heated up. Most would stay cold, but every now and then some would get warm, and sometimes I could hear some audible arcing. My only experience is at Ham Radio frequencies but I think it may still ...

2

To the best of my knowledge, it's only a matter of skin effect. Your shield should be larger than the skin effect of your electromagnetic field, to be able to fully reflect it (minus some losses). There are just 2 rules: For any conductive material, the higher frequency you go, the thicker the skin effect is. For any conductive material, the less ...

2

I do not believe this will be an effective scheme. The $Q$ of a resonator, a number which describes the strength of the resonant peak, is given by $$Q=\frac{f_0}{\delta f}\approx f_0\frac{2\pi\ t_{RT}}{\ell},$$ where $f_0$ is the resonant frequency, $\delta f$ is the FWHM of the resonance, $t_{RT}$ is the round-trip time, and $\ell$ is the round-trip ...

2

I'd put this in the not possible/very difficult category. Simply because if you are dealing with RF your wavelength is going to be on the order of 10cm - 1m+ which is going to place a limit on the accuracy you can achieve with any simple method. I'd be interest if thinks it can be done and how. For other methods I think stereo vision or structured ...

2

There are a lot of methods for determining permittivities at high frequency, but they are uniformly experimentally-based. One of the easy methods is a resonant cavity. You create a resonant cavity that has a known resonant frequency. Then insert the material inside the cavity by some holder and see how much the resonant frequency is perturbed (using a vector ...

2

Yes, but it's unlikely. Damage from other frequencies will be limited because typical receivers have a pre-select filter after the antenna to filter out other frequencies. In band signals pass through a Low Noise Amplifier (LNA) directly after the antenna, which can saturate if the signal level is high, and fail if the signal level exceeds its maximum input ...

2

Ultra low capacitance diodes <1pF are capable of operating at GHz frequencies. They are low loss Schottky types. BAS69xxx from STMicro is one example.

2

No, not irrespective of modulation type. If you know that you need to deal with signals like that, you pick a modulation scheme that provides "gain" in the demodulation process. For example, GPS uses direct-sequence spread spectrum, which allows the wideband energy of the signal to be "refocused" to a narrow bandwidth, providing a huge amount of gain over ...

2

Generally when you need to scale up a clock you use a PLL (Phase lock loop). A very crude explanation is that you have a voltage controlled oscillator at roughly the required frequency. You divide the output of this down to your reference frequency (a factor of 60 in this case) and then compare it to your reference clock input. The difference between the ...

1

Per the datasheet "RF1 and RF2 are reflective shorts when “OFF”". For best results consider the following configuration. Also per the datasheet below is the suggested interface for logic signal A and B I suggest try using TTL logic to drive the logic signals References: HMC784AMS8GE GaAs MMIC 10 WATT T/R SWITCH DC - 4 GHz

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They are the extremes of the voltage at the input which define the required 0 and 1 logic levels. On the data sheet Logic 1 must be at least 2.0v and logic 0 less than 0.8 to function properly.

1

You are correct. In the attached document shows minimum 2.0V and above is considered Logic High. Likewise maximum voltage of 0.8V and below is considered logic low.

1

The old analog signal TVs had a wide frequency range allocated to each channel. Channel 2 for instance occupied everything between 54 MHz and 60 MHz. Because of effects of temperature and other conditions on the hardware (e.g. resistors and capacitors), the transmitter and the receiver could drift slightly from the exact frequency. To compensate, the TV had ...

1

you can use plastic light gauge garden netting. They come in typical sizes of 50ft by 50ft at approximately under 10cents/sqft. They can be secured by thin cords to stakes or anchors.

1

All channels good but: National standards can control some parameters (gain, numbers of channels, gain in channel ...). Gain of Channel 1 can be less in some cases. I have 19 visible ssids in my workplace so channel is best if it only my and have no neighbors. often if no activity wifi routers choose channel 6, and it`ll be the most loaded. often all ...

1

ELF will likely be very problematic for you practically; remember that your antenna will have to be on the order of a wavelength to transmit or receive such a signal. Even for a 1/4 wavelength antenna, a 30 Hz antenna is 2500 km long. ULF has some history of amateur radio use, so at least it is feasible - and there are commercial antennas made by Aaronia ...

1

Even when connected to the same antenna, two identical receivers might come up with different navigation solutions. Their analog front ends have different sensitivity and noise figures as a result of normal manufacturing tolerances. Their internal clocks are not synchronized, and among other things, these effects might cause them to choose different subsets ...

1

Static field effects on devices Strong static magnetic fields will have little effect on most electronics, including most of the ones on your list. We routinely placed basic electronics in 1-2T fields, and never had any real problems. There are some exceptions though (this is probably not a complete list): Relays work by using a magnet to move a piece of ...

1

Ultra low capacitance diodes <1pF are capable of operating at GHz frequencies. They are low loss Schottky types. BAS69xxx from STMicro is one example.

1

I think you're looking for Schottky diodes.

1

The basic approach is correct, but it won't be as easy as just slapping a diode there, for several reasons: If you are receiving the signal with an antenna, the power level will be very small. A typical value might be -40dBm, which equals 0.1µW. In a 50 ohm load, this would be 2mV of voltage and 44µA of current. Diodes have forward voltage ranging from ...

1

SDR is normally done with I (in-phase) and Q (quadrature) channels. You can think of them as the two components of a complex number. These allow you to preserve the phase information through your signal processing chain, which is important for some kinds of modulation. For more information about what this entails, you should browse our related DSP.SE site.

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The main factor limiting FM signal reach is often the height of transmitter and receiver antennas over ground, not the power. The Earth is curved and antennas must be in (or very close to) the zone of direct visibility (you should be able to see one antenna from the top of another). Longer waves can bend over the Earth curvature, and short waves (the source ...

1

If the meter is correctly connected between the charger and the phone then it will show the current that the phone as a whole is drawing. However, that does not mean that it necessarily shows the current that the phone's internal electronics are drawing. It may not be obvious, but, current INTO the phone and current presently being used by the phone can ...

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