Piotr Kaminski

K-band FMCW radar module with interferometic capability for industrial applications

A newly developed, low cost FMCW radar system for industrial applications operating in K band has been presented. The radar features interferometric capability, which gives it sub-millimeter accuracy in distance variation measurement. Moreover, the presented radar has fully embedded signal processing with real time monitoring capability, thus making the presented sensor suitable for fully autonomous operation. The radar performance has been experimentally verified. Mean accuracy better than 30 μm has been achieved in displacement measurement test. The obtained results in terms of high accuracy and high measurement repetition rate prove the radar capable of meeting rigorous requirements of applications like structural health monitoring or industrial process control.

A Broadband 3 dB Tandem Coupler Utilizing Right/Left Handed Transmission Line Sections

A new type of broadband 3 dB tandem coupler has been proposed featuring frequency characteristics of the resulting coupling similar to those of a classic 3 dB two-section asymmetric coupled-line directional coupler. The coupler is composed of two loosely coupled-line sections having electrical lengths close to quarter-wavelength connected by right-handed and left-handed transmission line sections. Theoretical analysis and design equations have been presented with an exemplary realization. Measurements of the manufactured tandem coupler operating at f0 = 1 GHz having wide operational bandwidth have been shown to validate the presented analysis.

Reduced-Length Two-Section Directional Couplers Designed as Coupled-Line Sections Connected With the Use of Uncoupled Lines

Broadband coupled-line directional couplers having the properties of two-section coupled-line directional couplers are proposed. The presented couplers are composed of two-coupled line sections having the same coupling coefficient which are connected with the use of two sections of uncoupled transmission lines. It is shown that in such a structure it is possible to achieve an equal-ripple coupling characteristic similar to the coupling response of classic-two section coupled-line couplers. It is also shown that, in comparison to the classic counterparts, in the proposed couplers the required coupling between the coupled-lines is slightly weaker and the overall electrical length is reduced. The theoretical analysis and measurement results of a 3 dB directional coupler operating at a center frequency of 1.8 GHz are presented.

Broadband miniaturized butler matrix utilizing left-handed transmission lines

A novel concept of 4 × 4 Butler matrix realization has been proposed. The proposed Butler matrix is composed of four miniaturized coupled-line 3-dB/90° directional couplers. A broadband phase response has been ensured by the application of two left-handed transmission-line sections. The proposed concept has been experimentally verified by the design and measurements of a 4 × 4 Butler matrix, having center frequency equal to 1 GHz.

Broadband 4 × 4 microstrip antenna array utilizing slot-coupled power dividers

A 4 × 4 microstrip antenna array designated for 24 GHz FMCW radar systems featuring 2 GHz bandwidth is presented. The antenna array uses a stacked laminate structure composed of three dielectric layers. In the proposed antenna the power distribution is provided by series feeding across linear antenna subarrays with the use of inclined slot-coupled power dividers coupled to the straight transmission lines which feed these linear antenna subarrays. The broad impedance bandwidth has been ensured by application of parasitic elements located on the top metallization layer. The design and measurement results of the manufactured antenna array are shown.