This study is focus on the integration and miniaturess of the active circuit and antennas. Recently, the monolithic microwave integrated circuits have been mature in communication markets and the associated handsets are interesting in the quality and profile. The antenna plays a role as a radiator in wireless system. Therefore, the performance dominates the quality of communication. The aspect of the antenna usually occupies the majority communication hardware¡¦s area. Comparing many front end circuit elements, the challenges in the antennas will be more crucial. Therefore, it has well merits in designing high integration and bandwidth antennas. Based on the integration of the active circuits stage and antennas, this work presents the aperture coupled active antenna with harmonic suppression and broadband dual feeds circularly polarized patch antenna. Utilizing the bented aperture and insertion of narrow rectangular slots on excitation edge for shifting the high order harmonic components from the active stage, the harmonic suppression characterization is implemented by the above approach. The other active antenna, braodband dual feeds circularly polarized antenna, is achieved with spatial power combining. The subject aims the different excitated patch structures and replacing the periodic feeding lines as active circuits in the discussion. Relative to the conventional 50 Ohm feeds, the mechanics of the feeds are modified with stepped impedance resonators and stubs at the same physical wave length condition for achieving the integration of the antenna and the circuit. Besides, this antenna can exhibit excellent behavior and compact the size in the effective frequency range.

Active integrated antennas (AIAs) are divided into oscillator type AIAs, amplifier type AIAs and frequency-conversion type AIAs. The AIAs designed in this master thesis are oscillator type. Instead of using lumped component like inductors and capacitors, I use a half-wavelength antenna as resonator. In this design, antenna is also treat as a radiated loading. According to reciprocity, antenna receives the reflection signal affected by human body movement and vital sign at the same time. This behavior is regarded as a self-injection locking oscillator. In this master thesis, active antenna is used in monitoring and contacting measurement. In monitoring measurement, active antenna and subject keep their distance. Subject random body movement affects the measured result. Contacting measurement means active antenna pastes on the subject, thus there is no relative displacement between active antenna and subject. Random body movement affect iscancelled in theory. In contacting measurement design some different body motions to test the tolerance of this measurement structure, and use correlation to cancel random body movement. The sensitivity of active antenna structure is enough to detect the vocal vibration in contacting measurement.