Issue link: https://resources.mouser.com/i/1484091
17 Qorvo 2022 Figure 4: Comparison of QPQ2200Q to LTCC: B47 BAW filter rejects 5GHz UNII 1-3 bands. (Source: Qorvo) Figure 5: V2X—Wi-Fi antenna isolation needed to achieve a reliable V2X link: QPQ2200Q B47 vs. LTCC. (Source: Qorvo) The LTCC is filtering only broadband frequencies. The B47 BAW filter offers similar insertion loss as the LTCC filter, but also provides high rejection of the 5GHz UNII 1-3 bands. The B47 BAW filter can replace the LTCC filter on the Tx/Rx path, or it can be placed on the Rx side only. Figure 4 illustrates how the LTCC filter provides no rejection of the UNI-3 band and poor rejection in the UNII-2 and UNI-1 bands. Next, let's look at the comparison of LTCC vs. B47 V2X coexist filter from a systems and implementation standpoint. Figure 5 compares V2X— Wi-Fi antenna isolation needed in order to achieve a 1,000-meter V2X link. The plot to the left shows a V2X system (TCU + active antenna) with only an LTCC filter on the Tx path and requiring greater than 80dB antenna isolation, which could be difficult to achieve in practice. The plot to the right shows a V2X system with a B47 V2X coexist filter in the TCU and active antenna requiring only 15dB antenna isolation in order to achieve a 1,000-meter V2X link. If design/systems engineers can achieve >20dB antenna isolation, they may need only one V2X coexist filter in the active antenna. Besides in-car Wi-Fi, there is another use case to be considered when deciding on filtering solutions, whether the car has built-in Wi-Fi capability or not, and that is when the antenna isolation is dictated by the passengers using Wi-Fi hotspots in their mobile phones. Qorvo's filter products use patented BAW technology optimized to address complex selectivity requirements, from 1.5GHz up to 6GHz in standard footprints. For example, the Qorvo QPQ2200Q filter is the world's first filter to address coexistence of V2X with 5.6GHz Wi-Fi for autonomous vehicles. Another example is the Qorvo QPQ2254Q 2.4GHz Wi-Fi filter, designed to enable coexistence with LTE B40 and B41. These filters also offer a smaller footprint than ceramic filters, which adds to design flexibility.