The SKY67111-396LF is GaAs, pHEMT Low-Noise Amplifier (LNA) with an active bias structure and very high (+39 dBm OIP3) linearity. The advanced GaAs pHEMT enhancement mode process also provides excellent return loss (18 dB) and very high gain (20 db) coupled with very low noise figure (0.5 db). In addition, the internal active bias circuitry provides stable RF performance over temperature, and process variation. The device offers the user the ability to externally adjust both supply current and gain. It also includes a power down feature with associated integrated enable/disable circuit. The target market for this device is cellular infrastructure.
Supply voltage is applied to the RFOUT/VDD pin through an RF choke inductor. Pin 4 (VBIAS) should be connected to RFOUT/VDD through an external resistor to control supply current. The RFIN and RFOUT/VDD pins should be DC blocked to ensure proper operation. Pin 6 (ENABLE) is connected to a logic “low” (or grounded) to enable the output and a logic “high” to disable the output and greatly reduce current draw. Pin 5 (FEEDBACK) is connected through an RC network to externally adjust the gain of the device with affecting the noise figure of the LNA.
The SKY67111-396LF operates in the frequency range of 0.7 to 1.2 GHz and a standard evaluation board is available. Custom evaluation board schematic designs can be generated for application specific narrow band requirements such as improved gain flatness or higher linearity. For lower frequency operation (0.3 – 0.7 GHz), the upcoming pin-compatible SKY67110-396LF should be used. The LNA is manufactured in a compact, 2 x 2 mm, 8-pin Dual Flat No-Lead (DFN) Skyworks Green package. Samples are available upon request.