An approach for the parallelization of dielectric measurements at microwaves within a lab-on-a-chip environment is presented. Its targeted application is the simultaneous monitoring of a cell suspension in microfluidic channel arrays under the influence of different drugs e.g. for an effectiveness assessment. The method has the advantage that only a single network analyzer and no other microwave components like switches or multiplexers are necessary. The paper presents the concept of the measurement system, prototype sensors, and their characterization. The realized devices operate between 20 and 25 GHz and have been tested with water, water-ethanol mixtures and Chinese Hamster Ovary (CHO) cells.