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It is unlikely you will be able to get a Colpitts oscillator oscillating at 400 MHz on a solderless breadboard. The parasitic capacitances and inductances will almost certainly limit the maximum oscil …

Is it possible to measure the distance between two devices by using RF signal strength if the devices have no obstructions between them? If so then can 2 or 3 be used to get distance and direction? … It is theoretically possible to measure distance between two devices using the signal strength of an RF signal. However, that is not a common approach, and it is likely to be impractical. …

am trying to understand fully the problem with using electrically short antenna to transmit RF signals (i.e length significantly shorter than the intended wavelength). …

However, I encountered a problem where once the component gets small enough (I want a frequency in the hundreds of MHz range), the oscillation stops? The loop gain becomes less than 1, at the intend …

In an ideal world, a 4-port directional coupler would do the trick. A directional coupler is similar to a "hybrid coil" used to allow bidirectional communication in analog telephone lines. I have copi …

Given that Q = R/sqrt(L/C), why not maximise Q by setting L huge and C tiny? There are several issues to consider. The first is the impedance of the tank network. Although the Q varies as \$\sqrt{L/ …

Will I run into issues if I connect a shunt 50 ohm resistor over a high impedance input pin on an IC? One result that may or may not be an "issue" is that the voltage at the high impedance input pin …

In literature it is routinely said that an electric field generates a magnetic field A changing electric field will generate a magnetic field. That, I believe, is what the literature routinely says, …

Current through the center conductor of a coaxial cable needs to return to its source (possibly via capacitance, i.e. displacement current). If it does not return via the coax outer conductor, it must …

Why do they cancel? A signal that is fed into port 1 (of the handbook's figure 2.20) travels around the coupler in both directions. That part of the signal that travels clockwise around the coupler …

Can 50 ohm attenuators be employed to attenuate the signal? Yes, if you use a 50 \$\Omega\$ feed-thru terminator (or a Tee connector with a 50 \$\Omega\$ terminator attached to one of the ports) at …

Why does a loop antenna not measure the differential magnetic field? Electromagnetic waves, when they are far from the source, and far from electrically conductive or ferromagnetic materials, have e …

It looks like the box might be conductive. If so, the current that flows through the shields of the external coaxes gets divided. Some of that current flows through the shield of the internal coax, ca …

Transmission line effects depend upon ratio of the length of the transmission line to the wavelength of the highest frequency of interest traveling along the transmission line. If the length of the tr …

As others have pointed out, if the transmission line is "short" relative to the signal wavelength, then one can usually ignore transmission line effects. However there is a point you raised that I wou …