Issue link: https://resources.mouser.com/i/1517877
8 Experts on Overcoming Challenges of RF Solution Design 26 smaller battery. Such a configuration is ideal for collecting patient data that goes through a smartphone app to the cloud, where remote doctors can see it for medical diagnosis. Part of product development, then, involves creating the smartphone app and the RF data interface. Another challenge is finding a wireless module that meets RF and data processing requirements but also comes in the right physical package. For wearable medical devices, package size is important. In some wearables, comfort, such as an ultrathin design, is a key consideration. Such a device may also require a flexible design so that as the person moves, the device can bend without damaging components. Often, smaller and more compact packages must be more power efficient because small packages do not dissipate heat as well as a large packages. We use wireless modules instead of designing our own RF circuit because doing so simplifies the engineering. A module contains everything: the RF section, chip antenna, and matching circuit. You just need to connect it to a few external components. For some designs, such as those that can flex without damaging components, we use just the wireless chip, which is in a very small package. In such cases, we use a vendor-provided reference design for the matching circuit. Component sourcing is critical. You have many vendor choices for BLE and other wireless modules and chips. Using precertified components helps streamline certification testing, which takes a lot of time and money. Cost is an important criterion for us because some of our products are disposable or semidisposable, but all our devices have a long market life—between five and ten years. That means that we need parts from sustainable chip vendors that can support manufacturing for many years. We also look for vendors based in the United States, with good facilities and a good reputation, and we want vendors with a good support plan. It's important to build the vendor relationship. You can get a feeling about a vendor by the way it responds to your questions. ''We need parts from sustainable chip vendors that can support manufacturing for many years."