High order harmonics generator
View Patent ↗A high-order harmonics generator includes a plurality of high-pass filters to block out DC signals. In one embodiment, high-pass filters are coupled to the output signals from an envelope detector and a power detector. A high-pass filter can also be coupled to the output of a multiplier that multiplies the filtered envelope signal and the filtered power signal. Additional multipliers may also be used at outputs of multipliers in a cascaded chain of multipliers for higher harmonics generation.
1. A harmonics generator, comprising:
a power detector configured to receive an RF input signal and output a power signal;
an envelope detector configured to receive the RF input signal and output an envelope signal;
a first high-pass filter configured to receive the envelope signal and output a first signal;
a second high-pass filter configured to receive the power signal and output a second signal;
a first multiplier configured to multiply the first signal with the second signal and output a first product signal;
a second multiplier configured to multiply the second signal with the second signal and output a second product signal;
a third high-pass filter configured to receive the first product signal and output a third signal;
a fourth high-pass filter configured to receive the second product signal and output a fourth signal;
a third multiplier configured to multiply the first signal with the fourth signal and output a third product signal;
a fourth multiplier configured to multiply the second signal with the fourth signal and output a fourth product signal;
a fifth high-pass filter configured to receive the third product signal and output a fifth signal; and
a sixth high-pass filter configured to receive the fourth product signal and output a sixth signal.
2. The harmonies generator of claim 1 , wherein the first, second, third, fourth, fifth, and sixth signals are used in a predistortion application.
3. The harmonics generator of claim 1 , wherein the first, second, third, fourth, fifth, and sixth high-pass filters have the same cut-off frequency.
4. A method of generating harmonics from an input RF signal, the method comprising:
detecting envelope information from the RF signal;
detecting power information from the RF signal;
filtering out DC components from envelope and power information to generate a first signal and a second signal;
multiplying the first signal with the second signal to generate a first product signal;
multiplying the second signal with itself to generate a second product signal;
filtering out DC components from the first product signal to generate a third signal;
filtering out DC components from the second product signal to generate a fourth signal;
multiplying the first signal with the fourth signal to generate a third product signal;
multiplying the second signal with the fourth signal to generate a fourth product signal;
filtering out DC components from the third product signal to generate a fifth signal: and
filtering out DC components from the fourth product signal to generate a sixth signal.
5. The method of claim 4 , wherein the filtering also filters out low frequency components.
6. The method of claim 4 , wherein the first and second signals are used by predistortion applications.
7. The method of claim 4 , wherein the first and second signals are harmonics of the RF input signal.