Systems, methods, assemblies, and components for aftertreatment of an engine can comprise an aftertreatment module including an exhaust enclosure with at least one inlet port to receive exhaust gas, an outlet port to output exhaust gas, a first compartment, and a second compartment; a plurality of particulate filters extending in parallel with each other within the exhaust enclosure such that, for each of the particulate filters, an inlet of the particulate filter is in the first compartment and an outlet of the particulate filter is in the second compartment; and at least one radio frequency (RF) sensor set including an RF transmitter assembly and an RF receiver assembly. The RF transmitter assembly can be provided in the first compartment at the inlet of one of the particulate filters, and the RF receiver assembly can be provided at the outlet of said one particulate filter.