Active window glass antenna system with automatic overload protection circuit

A method of operating an active antenna system with overload protection:

• receiving a signal from an antenna;
• supplying the received signal to a direction coupler;
• delivering a first portion of the received signal from the direction coupler to an electronic switch and a second portion of the received signal to a detector;
• amplifying the second portion of the signal by an amplifier and supplying the amplified signal to a comparator;
• comparing, by the comparator, between the amplified second portion of the signal and a reference signal;
• determining whether the amplified second portion is, (i) less than or equal to a first reference signal, (ii) greater than the first reference signal, (iii) greater than a second reference signal;
• passing the first signal portion to a RF amplifier when the second signal portion is less than or equal to the first reference signal, wherein the RF amplifier is supplied with a full signal;
• passing the first signal portion to the RF amplifier, when the second portion of the signal is greater than a first reference signal, wherein the signal supplied to the RF amplifier is decreased;
• activating the electronic switch to switch the first portion of the signal to a bypass path, when the comparing step finds the second portion of the signal is greater than a second reference signal;
• matching the signal on the bypass path to a selected impedance value;
• and
• delivering the impedance matched signal to a radio.

A method of operating an active antenna system which receives an antenna signal from an antenna:

• designing an electronic switch system to receive at least a first portion of an antenna signal;
• designing a detector to receive at least a second portion of the antenna signal;
• determining whether the second portion is, (i) less than a first reference signal, (ii) greater than the first reference signal, (iii) greater than a second reference signal;
• passing the first signal portion to a RF amplifier when the second signal portion is less than the first reference signal, wherein the RF amplifier is supplied with a full signal;
• decreasing the signal to be supplied to the RF amplifier when the second portion of the signal is greater than the first reference signal;
• passing the decreased first signal to the RF amplifier;
• activating the electronic switch to switch the first signal portion to a bypass path, when the second portion of the signal is greater than the second reference signal;
• and
• delivering bypass antenna signal to the load.

An active antenna system comprising:

• an RF amplifier configured to receive signals from an antenna;
• a load in operational connection to the RF amplifier;
• an overload protection circuit in operational connection to the RF amplifier, and including a first operational arrangement and a second operational arrangement,
• the first operational arrangement including,
• a detector system configured to detect at least a portion of an antenna signal, as a representative value of the antenna signal;
• a first reference signal;
• an amplifying amplifier configured to receive at least a portion of the antenna signal and to selectively generate a control signal;
• a variable attenuator connected to the amplifying amplifier and the RF amplifier, the variable attenuator being altered dependant upon the value of the control signal;
• a first path, including the RF amplifier, from the input to a load, the first path provided with a full antenna signal when the antenna signal is less than the first reference signal, and is provided with a reduced antenna signal when the antenna signal is greater than the first reference signal;
• the second operational arrangement including,
• the detector system configured to detect at least the portion of the antenna signal, as the representative value of the antenna signal;
• a second reference signal;
• a comparator system configured to compare the second reference signal and the detected antenna signal;
• and
• a second path from the input to the load, wherein the second path bypasses the RF amplifier, and is provided with the antenna signal when the output of the comparator indicates the value of the antenna signal is greater than the second reference signal.