RF amplifier tuning method for coping with expected variations in local dielectric

摘要

A wireless sensor capable of sensing and measuring at least one ambient parameter is disclosed herein. The wireless sensor is capable of transmission of measurement values at a periodic rate, wherein the transmission rate is varied or non-varied. An amplifier varies a power transmission to the antenna based on a real-time soil conductivity value of a soil area and a real-time soil dielectric constant value of a soil area to improve a communication range and communication reliability of the antenna.

主权项

1. A wireless soil sensor comprising:
a microcontroller; an antenna; an amplifier; a probe conducting structure to be placed in the material forming a capacitor connected to a soil moisture circuit; a soil moisture circuit comprising a high frequency oscillator for applying electrical stimulus to the probe structure, a known reference capacitor connected in series to the high frequency oscillator, and a first voltage meter located between the high frequency oscillator and the reference capacitor; a soil salinity circuit comprising a low frequency oscillator for applying electrical stimulus to the probe structure, a known reference resistor connected in series to the low frequency oscillator, and a second voltage meter located between the low frequency oscillator and the reference resistor; wherein the respective circuits connect between the reference capacitor and the reference resistor, at which point the circuits are connected to the probe structure and a third voltage meter; and wherein the amplifier varies a power transmission to the antenna based on a real-time soil conductivity value of a soil area and a real-time soil dielectric constant value of a soil area to improve a communication range and communication reliability of the antenna.