###### Abstract
The measurement error was 15%, which is currently a high result for non-invasive glucose measurement methods. The main problem with this approach is the complexity of creating such sensors. The most common non-invasive methods for measuring glucose levels are radio frequency methods [10; 11]. Such methods are harmless to the human body and do not require piercing of the finger or other parts of the body. The authors of [10] use a wireless microstrip sensor with information transmission over the air using Vivaldi antennas.The authors used water as a measured substance with the addition of glucose contained in the liquid in a volume of 20%, 25% and 30%. Measurement of the transmission coefficient showed a shift of the resonance frequency of 0.1 GHz with a change in the glucose content in water from 20% to 50%. The main problem with this device is that the test piece must be placed between the ports of the device, and the transmitting antennas are large compared to the sensor itself. The authors of [11] created a microstrip sensor based on a resonant design, which made it possible to achieve acceptable results (the authors do not indicate exact numbers). The article considered two resonant frequencies of 3.41 and 3.81 GHz. The difference in the amplitudes of the transmitted signal when measuring deionized water with glucose was in the range of 0.04-0.2 g/mL. In this case, the value of the transmitted signal for the entire range of changes in glucose concentration was 0.87 dB. The disadvantage of such a sensor is a rather narrow frequency band in which the response of the system to a change in glucose concentration is observed. This article proposes to consider a near-field microwave probe in the form of a combined emitter (a combination of a symmetric dipole and an annular frame) or a folded dipole as a possible promising antenna for non-invasive monitoring of glucose concentration. The near field created by such a probe penetrates into the investigated medium deeper than the field of resonant microstrip antennas. Structurally, the probe differs from the existing microwave analogs in that the probe is more resistant to mechanical stress than analogs on a dielectric substrate. These design features make it possible to reduce the size of the probe without major structural changes and scaling the probe will not affect the radiation power loss in the near field. Previously, the authors have carried out theoretical studies of this near-field probe [18], which showed a sufficient depth of penetration of the signal generated by such probes into biological media and the possibility of using this design for non-invasive measurements, in particular, to measure the concentration of glucose in biological tissues. Theoretical modeling of the interaction of a bidirectional probe with a multilayer structure showed the probe sensitivity of 0.55-0.86 dB/(mmol/L). The layer with dielectric properties of blood with different glucose concentrations was investigated here.The purpose of this work was a more in-depth study and experimental verification of this near-field probe design. The study was carried out for a bidirectional probe and a unidirectional one.