Coupling network

A coupling network for coupling a signal at a frequency from a transmitter to a antenna, said transmitter having a source resistance, said antenna having a load resistance and a load reactance, the ratio of said load reactance to said load resistance greater than 100, said coupling network comprising:

• a reactive element arranged in series with said antenna to resonate with said load reactance at said frequency;
• and
• a delay circuit between said reactive element and transmitter, having a delay equivalent to a quarter wave length transmission line at said frequency and having a characteristic impedance equal to the square root of the product of the values of said load resistance and the source required load resistance, said source required load resistance defined as the resistance seen looking into the input of the coupling network.

In combination, a voltage source providing a signal at a frequency, a load, and a coupling circuit interposed between said voltage source and said load, said voltage source having a source resistance, said load having a load resistance and a load reactance, the ratio of said load reactance to said load resistance greater than 100, said coupling circuit comprising:

• a reactive element arranged in series with said load to resonate with said load reactance at said frequency;
• and
• a delay circuit between said reactive element and said source, having a delay equivalent to a quarter wave length transmission line at said frequency, and having a characteristic impedance equal to the square root of the product of the values of said load resistance and the source required load resistance, said source required load resistance defined as the resistance seen looking into the input of the coupling network.