Binary coded, arbitrarily shaped received signal strength indicator

摘要

A received signal strength indicator (RSSI) receives an input voltage. The input voltage is amplified by a cascade of voltage amplifiers. The output of each amplifier is squared by a squarer. The output of each squarer is then compared to an array of fixed values from a strictly monotonic sequence. The comparators outputs are fed to a digital thermometer decoder, the outputs of which represent the binary coded, arbitrarily shaped RSSI. The squarer can be implemented using two MOS transistors, and has a current output. The comparators can be implemented using multiple current mirrors.

主权项

1. A binary coded, arbitrarily shaped received signal strength indicator circuit comprising:
an input of said circuit; a binary-coded digital output; an array of cascaded voltage amplifiers, wherein said input of said circuit is connected to the input of the first amplifier; an array of signal squarers, having as many squarers as voltage amplifiers, wherein an output of each voltage amplifier is connected to an input of one, and only one, squarer; an array of comparing blocks, having as many comparing blocks as squarers, wherein each comparing blocks comprises:
an input, connected to one, and only one, squarer output;an array of comparators, wherein each comparator compares a representation of said input of the comparing block to a fixed value, wherein all the fixed values form a strictly increasing sequence; andan array of digital outputs, having as many digital outputs as comparators, each said digital output being connected to the output of a comparator; a digital thermometer decoder, comprising:
an array of inputs, having as many inputs in the array as comparators in the entire circuit, wherein each said digital output of each comparing block is connected to an input of the digital thermometer decoder; andan array of outputs; and an array of outputs of said received signal strength indicator, wherein each said output is connected to an output from the array of the digital thermometer outputs.