# Dielectric Losses

Dielectric loss quantifies a dielectric material's inherent dissipation of electromagnetic energy. It loss of energy that goes into heating a dielectric material in a varying electric field.

For example, a capacitor incorporated in an alternating-current circuit is alternately charged and discharged each half cycle.

During the alternation of polarity of the plates, the charges must be displaced through the dielectric first in one direction and then in the other, and overcoming the opposition that they encounter leads to a production of heat through dielectric loss, a characteristic that must be considered when applying capacitors to electric circuits, such as those in radio and television receivers.

Dielectric losses depend on frequency and the dielectric material.

Dielectric Loss is measured using the Loss of tangent which is also commonly referred to as tan delta (tan δ). The value of tan delta is high means Dielectric Loss is also high.

## Loss Tangent

Loss Tangent or tan δ is a dimensionless quantity. Loss Tangent tends to calculate the estimated Loss of signal because of the fundamental dissipation of electromagnetic energy that takes place in the substrate of the printed circuit board.

### D = tanδ = cotθ = 1/(2πRpCp)

where,

tanδ = The Loss angle

θ = The phase angle

f = The frequency

Rp = Equivalent parallel resistance

Cp = Equivalent parallel capacitance

The Loss Tangent has a vital part in extremely high frequencies above 1 GHz, The analog signals to decide the signal attenuation.