US 2008/0290938 A1 · Multibit digital amplifier for radio-frequency transmission

Abstract

A broadband multibit digital radio-frequency (RF) signal is synthesized digitally. to convert the digital signal to a high-power analog signal for RF transmission. Each bit (or cluster of bits) of the digital signal is first separately amplified using a fast switching amplifier with a controlled dc power supply voltage. The DC voltages are weighted to match the significance of the bits, and controlled by a set of calibrated DC reference sources to maintain high precision. The amplified digital signals from the various bits are then combined and passed through an appropriate analog filter to generate the RF signal to be transmitted. Such a signal can exhibit broad bandwidth, high dynamic range, excellent linearity, and low noise. Preferred embodiments of this system can incorporate superconducting electronic elements. For ultimate precision, a set of primary or secondary DC voltage standards can be used to regulate the switching amplifier supply voltages.

Claims18

Dependent claims

A multibit digital amplifier circuit comprising:

an N bit digital radio frequency (RF) signal present on N different lines, one bit per line;
where the N bits have an order ranging from the least significant bit (LSB) to the most significant bit (MSB);
where N is an integer greater than 1;
N amplifiers, one amplifier per bit, each amplifier having a signal input, a signal output and at least two power terminals for the application therebetween of an operating voltage for the amplifier;
means for applying each bit to the signal input of its corresponding amplifier;
and
means for applying an operating voltage to each amplifier corresponding to the order of the input bit applied to the amplifier for converting its input bit to a voltage indicative of the order of the input bit.

4 more elements

A multibit digital amplifier circuit comprising:

an N bit digital radio frequency (RF) signal present on N different lines, one bit per line;
where the N bits have an order ranging from the least significant bit (LSB) to the most significant bit (MSB);
where N is an integer greater than 1;
oversampling code converting means responsive to the N bit digital signal for converting the N bit signal into selected X groups of ordered bits present on X different lines;
each one of the X lines carrying a signal corresponding to the bits of its group;
where N and X are integers greater than one, and X is less than N;
X switching amplifiers, one switching amplifier per group, each amplifier having a signal input, a signal output and two power terminals for the application therebetween of an operating voltage;
means for coupling each one of the X lines to the signal input of its corresponding switching amplifier;
and
means for applying an operating voltage across the power terminals of each switching amplifier corresponding to the order of the group of bits applied to the signal input of the amplifier for converting the input signal to the amplifier into a voltage indicative of the value of the bit input signal.

7 more elements

Dependencies are inferred from the claim text.

Multibit digital amplifier for radio-frequency transmission

Life of this patent

Multibit digital amplifier for radio-frequency transmission

Life of this patent

Abstract

Claims18