What is the impedance of an antenna?
Impedance relates the voltage and current at the input to the antenna. The real part of the antenna impedance represents power that is either radiated away or absorbed within the antenna. The imaginary part of the impedance represents power that is stored in the near field of the antenna.
What is an impedance transformer?
Impedance is the current limiting characteristic of a transformer and is expressed in percentage. This percentage represents the amount of normal rated primary voltage which must be applied to the transformer to produce full rated load current when the secondary winding is short circuited.
How does an impedance transformer work?
The simplest way to match load impedance in AC circuits is to use a transformer — a highly efficient device that transfers electrical energy from one circuit to another through electromagnetic induction: Two coils of wire (windings) are wrapped around an iron or ferrite core, and when the primary winding experiences …
How does impedance affect a transformer?
The per-unit impedance describes that percentage of the rated voltage required to produce full load current while the transformer output is shorted. The lower the impedance, the lower the voltage required to produce full load current.
Which transformer is suitable for impedance matching?
Zs represents the secondary, or load, impedance (ZL). The highly efficient transformer essentially features a wide bandwidth. With modern ferrite cores, this method is useful up to about several hundred megahertz. An autotransformer with only a single winding and a tap can also be used for impedance matching.
What is the impedance of a tranceiver transformer?
This means that the end fed wire antenna, which has a very high impedance of around 2500 Ohm, is transformed to an impedance of 50 Ohm. This impedance suits best to most tranceivers. The transformer consists of 2 primary windings and from 14 secondary windings.
What is the impedance of an end fed antenna?
The feeding point of a multiband End Fed antenna is practically a wide band impedance transformer. This means that the end fed wire antenna, which has a very high impedance of around 2500 Ohm, is transformed to an impedance of 50 Ohm.
What should the impedance of a half wave transformer be?
The goal of the impedance transformer is match the 50 ohm impedance of the feedline (coaxial cable) with the potential 3000 to 4000 ohm impedance expected from an end-fed half wave antenna wire radiator.
What kind of antenna matching transformer do I Need?
The matching transformer presented here can be used for any kind of receiving antenna where 300 to 75 ohms conversion is required and can be followed by 75 ohms input antenna amplifier.
