Dual frequency matching

Hi

Short question:
I have an upcoming design with 1 lora modem which supports 868 and 915 bands. The antenna I will use supports 868 and 915 MHz bands
The problem is the pi matching network needs to be designed to either 868 or 915 (according to antenna datasheets). Any workarounds to have a design that can work on 868 AND 915 after it has been assembled ?

Thanks!

The impedance matching network could be either single-band or wide-band.
The antenna could be designed to get good VSWR for single-band, for dual-band (or multiple bands), or for wideband.

If you spend some time tuning the pi matching network you may get about 10% bandwidth (from fo), so it will cover both, 868 and 915 MHz bands.

So it might be possible with just 1 pi matching network ?

As a simple example, a near ideal 0.5 lambda dipole, center freq. 900MHz, impedance 84+j30 Ohm, is tuned to cover 860-930MHz with lowest possible VSWR.
Brown curve in Smith chart shows measured antenna impedance before tuning and yellow curve after tuning network have been applied.
All are measured values, taking in account non ideal matching components.

Tuning network schema is inserted exactly in middle of dipole and consist of three components from Murata of size 0402. Caps are of type GJM1555 and inductor is of type LQW15.

A dipole is by nature relative wideband so even without any tuning is VSWR not that bad. VSWR before and after tuning: