The apparatus includes a sensor having a multi-portion dielectric composite. A microstrip transmission line is formed on the dielectric composite and includes an input section, radiator portion, and an output section. The dielectric material adjacent the radiator portion is selected to substantially match that of the certain portions of a live organism being sensed, allowing other constituents of the organism to be sensed. This allow the radiator portion to effectively respond as if it were embedded inside the organism, removing substantial uncertainly from the measurement process. By then applying a plurality of signals to the sensor, the reflected and transmitted components of the signal can be measured and used to determine the amount of certain constituents are present in the organism.
