Renesas Electronics has announced the availability of its ultra low-noise heterojunction FET (field effect transistor) product, the NE3520S03, which features the low noise characteristics for satellite broadcast reception applications. The FET features a semiconductor chip with an epitaxial structure that speeds up the electron velocity and substantially reduces the source resistance. Three-dimensional electromagnetic field analysis was used to improve the performance of the products at high frequencies in the gigahertz class, while a hollow plastic package was employed to allow easy replacement of the company's existing NE3517S03 product. These improvements result in a noise figure value of 0.65dB.
The product enables manufacturers of antennas for satellite broadcasts to improve the reception sensitivity of their products with signals such as high-definition TV broadcasts. Low-noise heterojunction FET products are used mainly in the LNB (low-noise block) converter of antennas for receiving satellite broadcasts and satellite data communications. They are the key devices used to amplify the weak microwave signals transmitted by satellites. A single LNB employs from 3 to approximately 20 low-noise heterojunction FET devices, and a low noise figure contributes to more stable reception and a high quality picture that is more detailed. To reduce noise at ultra high frequencies, the FET employs an epitaxial wafer structure that leverages high electron density, thin-layer technology. This increases the velocity at which the electrons move through the channels and lowers the source resistance, making possible a noise figure of 0.65dB, and an associated gain of 13.5dB. The structure of the hollow plastic package developed for 12GHz low-noise heterojunction FET products, and currently the industry standard, was optimised through the use of three-dimensional electromagnetic field analysis. This made it possible to extend the usable frequency range of the device to the 20GHz band. Fewer development man hours are required of customers replacing existing products with the FET because the performance of the semiconductor chip can be extracted efficiently while the input/output impedance remains almost the same as that of existing 20GHz band low-noise heterojunction FET products.
