A triple-band bandpass filter with at least one cavity resonator. Each cavity resonator has the same three orthogonal resonances modes corresponding to three unique resonance frequencies. The three unique resonance frequencies define the passbands of the filter. The filter has an input probe coupled to an input cavity resonator. The filter has an output probe coupled to an output cavity resonator. The input and output probes are shaped to concurrently couple signal waveforms in each of the resonance modes. Coupling probes that can be used as input or output probes are also provided. An inter-cavity coupling operable to concurrently transmit signal waveforms in each of the resonance modes is also provided. The inter-cavity coupling can be used to transmit signals between adjacent cavity resonators in the filter.