Green Laser Pointer The Ideal, Advanced And Reliable Safety Product

By Author: janney
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Using this feature, you can achieve electromagnetic shielding, while achieving a certain physical connectivity purposes. Method, the waveguide's cutoff frequency is designed to shield the electromagnetic wave is much higher than the frequency of the electromagnetic wave to be shielded by waveguide generated in a large attenuation. Because this application is the use of waveguide cutoff frequency, so as waveguide cut-off. The users don’t have to point the emitter of green laser pointer to the receiver when use a green laser pointer.As the concept is to shield the waveguide structure of one of the basic concepts of design. Common waveguide with circular, rectangular, hexagonal, etc., and their cut-off frequency is as follows:

Rectangular waveguide cut-off frequency: fc = 15 × 109 / l where: l is the largest rectangular waveguide opening size, the unit is cm, fc unit is Hz.

Circular waveguide cut-off frequency: fc = 17.6 × 109 / d where: d is the inside diameter of circular waveguide, the unit is cm, fc unit is Hz.

...
... Hexagonal waveguide cut-off frequency: fc = 15 × 109 / w Where: w is the largest hexagonal waveguide opening size, the unit is cm, fc unit is Hz.

There could be obstruction between the emitter of 200mW Laser Pointer and the receiver.As the waveguide absorption loss: fall waveguide cutoff frequency electromagnetic waves through the waveguide region, the decay will occur, this attenuation is called the absorption cut-off waveguide loss, absorption loss ended waveguide is calculated as follows

A = 1.8 × fc × t × 10-9 (1 - (f / fc) 2) 1 / 2 (dB)

Where: t is the length of the waveguide cut-off, the unit is cm,5mW laser pointer is the frequency of the signal of interest (Hz), fc is the cutoff waveguide cut-off frequency (Hz). If the concern is far below the cutoff frequency f waveguide cutoff frequency (f <fc / 5), is formulated simply as: A = 1.8 × fc × l × 10-9 (dB)

Circular cut-off waveguide: A = 32t / d (dB)

Rectangular (hexagonal) As waveguide: A = 27t / l (dB)

As can be seen from the formula, when the interference frequency is much lower than the cut-off frequency of the waveguide, if the length of a waveguide cross-section maximum size, the losses increase by nearly 30 dB.

The 100mW laser pointer  products transmit and control signals by radio wave. As the total shielding effectiveness of the waveguide: the waveguide cut-off shielding effectiveness of the absorption loss by the previously discussed some of the holes with the shielding effectiveness can not meet the shielding requirements, you can consider using a cut-off waveguide, the use of cut-off provided the depth of the waveguide additional loss increase shielding effectiveness.

 

16 cut-off waveguide design steps and precautions

1) The conductor must not be allowed through the cut-off waveguide, otherwise it will cause severe electrical leakage, which is a common mistake.

2) make sure to shield the waveguide relative to the frequency is off, and far higher than the cutoff frequency (5 times) the frequency of required shielding. Most manufacturers prefer to produce red  Blue Laser Pointer.

Cut-off waveguide design steps are as follows:

A) determine the maximum frequency shielding and shielding effectiveness SE Fmax

B) to determine the cut-off waveguide cut-off frequency Fc, the fc ≥ 5Fmax

C) According to Fc, Fc calculated using the equation waveguide cross-section dimension d

D) according to d and SE, the use of waveguide absorption loss formula waveguide length.

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