Effective IM2 Products Estimation for Two-Tone and W-CDMA Modulated Blockers in 3GPP Direct Conversion Receivers


As third-generation (3G) wireless networks are currently expanding in Japan (IMT-2000), Europe (UMTS), and the US (cdma2000), the need for low-cost, low-power consumption, and low form-factor user equipment (UE) is becoming important for the commercial development of 3G mobile handsets. The direct-conversion receiver architecture, with the proper use of silicon processes, circuit design techniques, and architecture implementation, represents a promising system solution for highly integrated platforms for 3G handsets. In this article, we present a commercially available, fully integrated, zero-IF receiver solution for 3G radios (Figure 1). The receiver-input, second-order intercept point (IIP2) requirement is discussed extensively in this paper, as it is a key specification for a direct-conversion receiver. Measurements, simulations, and calculations are presented specifically on this topic.