What is a quarter-wave stub?

(also quarter-wave line), a section of a microwave transmission line that is a quarter-wavelength long at the fundamental frequency being transmitted. The input impedance of a quarter-wave stub is inversely proportional to its load impedance.

What is a coax stub?

A: A stub is simply a short length of transmission line connected in parallel with the coax feeding an antenna. At the far end, the stub is terminated with either a short circuit or an open circuit.

What is a stub filter?

Stubs are used as filters by creating a short- or open-circuit at a specific frequency. The stub is then placed in a signal path to either pass or remove signals of that frequency. The left-hand figure below illustrates how a ¼-l open stub creates an apparent short-circuit.

What is the 1/4 wavelength rule?

It is that quarter wavelength rule of having enough space to absorb at least 25 % of the design frequency we are going after to absorb. If we take 40 Hz. the wavelength at 28′ in total length and divide that number by 4, we get a quarter wavelength of around 7′.

What is the significance of quarter wavelength?

A quarter-wavelength away from the open-circuit, the current and voltage oscillations are exactly the same as at a short-circuit, and vice versa. This reflects the fact that open circuit (Z=∞) is dual to short circuit (Z=0).

What are stubs explain?

1 : a short part remaining after the rest has been removed or used up a pencil stub. 2 : a small part of a larger piece of printed paper (as a check or ticket) kept as a record of the purpose of the paper. stub. verb. stubbed; stubbing.

How do you find a quarter wavelength?

The length should be one-quarter wavelength with respect to the signal propagating in the line. The free-space wavelength λ0=c/f at 10 GHz is ≅3 cm. Therefore, the wavelength of the signal in the line is λ=0.6λ0≅1.8 cm, and the length of the line should be l=λ/4≅4.5 mm.

What is quarter wavelength rule?

What is the application of quarter wave line?

The application of quarter wave transmission line is impedance matching and impedance inversion in size relevant electronic structures, another application in RF/DC coupling in transistor amplifiers.