While both Wi-Fi signals and microwave ovens operate within the same frequency range (2.4 GHz or 5 GHz), they have different power levels and characteristics, which lead to differences in their ability to pass through walls or other obstacles like concrete.
Wi-Fi signals, being relatively low-power and designed for wireless communication over a range of distances, are able to pass through materials like concrete walls to some extent. The signals can penetrate and be attenuated (weakened) by obstacles, including walls, but still maintain enough strength to be detected by Wi-Fi devices on the other side.
On the other hand, microwave ovens operate at much higher power levels than Wi-Fi devices. They emit electromagnetic waves at the same frequency as Wi-Fi, but their primary purpose is to heat food by using the energy from these waves. The high power and design of microwave ovens mean that the waves are contained within the oven cavity. The oven's metal casing prevents the microwave radiation from escaping and causing interference with other electronic devices, as well as ensuring user safety.
While Wi-Fi signals can pass through walls to some extent, the higher power levels and more focused nature of microwave ovens make it less likely for their waves to penetrate solid obstacles like concrete walls. The metal casing of a microwave oven acts as a Faraday cage, which helps contain the microwave radiation within the oven and prevents it from escaping and interfering with other devices in the vicinity.
It's important to note that while Wi-Fi signals can pass through walls, the signal strength and quality may degrade as they encounter more obstacles or thicker barriers. Factors such as distance, building materials, and interference from other electronic devices can affect the performance and range of Wi-Fi signals.