This news will not be about new fresh iPhone 7 smartphones. This phone is not on the market yet, so it is hard to say how good (or bad) antennas it has. However, I have found very interesting research paper in which scientists compare the power of signal receipted by the most popular smartphones. This methodology is much better than bars presented by the phone!
Have you ever wonder why you have the problem with mobile signal reception and your colleague does not? You may use the same mobile carrier, but you have different phones. The answer is very simple. Each smartphone has different antennas and receiving circuits, so the receipted signal has different power level. Also, the signal level depends on how you hold the phone. Do you remember the famous issue with reception in iPhone 4? Is it very hard to design good and small multi-band antenna for mobile device. Therefore, Apple cam up with great idea. They have decided to print an antenna on the smartphone housing. Unfortunately, they did not check the impact of human hand on the antenna performance.
The newest research results show that all modern Apple iPhone mobiles have issue with mobile signal reception.
This study was performed by Nordic scientists and you can read about methodology in the Mobile Phone Antenna Performance 2016 report. Before you start to analyze tables, you should know some details about presented values. For mobile devices the industry defines two parameters: TRP (Total Radiated Power) and TIS (Total Isotropic Sensitivity). The TRP value tells us how much power the mobile radiates to the base station (higher value is better). The TIS parameter describes the minimum level of power which is required to receive the data, i.e. 1 bar on the screen (lower value is better). The radiated power was measured when the phone is handled in right or left hand during the call. Generally, maximum transmitting power of mobile device is the range limitation for voice calls. In case of data transmission, the range depend on the minimal signal level, i.e. the smartphone sensitivity.