A mobile wireless communications device includes a circuit board carried by a housing and having RF circuitry and a processor operative with the RF circuitry. A keyboard is carried by the housing and includes a keypad array circuit. A keypad connector is carried by the keypad and is operatively connected to the RF circuitry and processor. A plurality of Key_Out and Key_In connection lines connect the keypad connector and keypad array circuit. Filters carried by the keyboard are connected into each Key_Out and Key_In connection line for reducing RF energy picked up from either the antenna or external interference and interfering with normal processor operation.