The design and integration of penta-band planar antenna with a low noise amplifier (LNA) for vehicular wireless applications is discussed in this research. By integrating antenna with a LNA, the return loss can be kept low with the increased bandwidth compared with a passive antenna with the same design. The performance of the passive antenna, LNA, and integrated active antenna (IAA) are individually validated with the aid of vector network analyzer. The designed IAA covers navigational frequencies 1.2 and 1.5 GHz, wireless communication frequencies 2.4, 3.3 GHz and dedicated short range communication frequency 5.8 GHz, with LNA gain (>10 dB) and noise figure (<2 dB). The proposed design gives room for simultaneous reception of all the desired frequency bands with better performance for vehicular communications.

In radar receivers, the low noise amplifier (LNA) must provide very low noise figure and high gain to successfully receive very low signals reflected off of illuminated targets. Obtaining low noise figure and high gain, unfortunately, is a well-known trade-off that has been carefully negotiated by design engineers for years. This paper presents a fundamental solution method for the source reflection coefficient providing the maximum available gain under a given noise figure constraint, and also for the lowest possible noise figure under a gain constraint. The design approach is based solely on the small-signal S-parameters and noise parameters of the device; no additional measurements or information are required. This method is demonstrated through examples. The results are expected to find application in design of LNAs and in real-time reconfigurable amplifiers for microwave communication and radar receivers.