picohenry

The picohenry is a unit of electrical inductance. It is a submultiple of the henry, the base SI unit of inductance. One picohenry is equal to 10 to the power of negative twelve henrys (1 pH = 10⁻¹² H). This unit is commonly used in electronics, particularly in the design and analysis of high-frequency circuits, resonant circuits, and filters.

Inductance is a measure of an electrical conductor's ability to store energy in a magnetic field created by the electric current flowing through it. The henry itself is a relatively large unit, so smaller units like the picohenry and nanohenry are more practical for describing the inductance of small components such as inductors, coils, and the parasitic inductance found in circuit board traces and component leads. For example, a tiny surface-mount inductor might have an inductance value in the range of a few picohenrys.

The picohenry is also relevant when considering the behavior of very fast electrical signals. At high frequencies, even small amounts of inductance can significantly affect circuit performance, leading to impedance mismatches or unwanted resonance. Therefore, precise measurement and control of inductance at the picohenry level are crucial in areas like radio frequency engineering and microwave circuit design.