A radiation device configured for dielectrically heating, in particular cooking, of one or more objects , such as foodstuff, with high frequency radiation in the radio frequency range and/or microwave frequency range in a cavity of a heating appliance , in particular a cooking appliance , comprising: - at least one solid state power amplifier module with at least one input port and at least one output port , the solid state amplifier module configured for amplifying radio frequency and/or microwave frequency signals received at the input port , and for outputting the amplified radio frequency and/or microwave signals at the output port ; - at least one antenna coupled to the output port of the solid state amplifier module and at least configured for emitting radio frequency or microwave frequency radiation based on the signals from the output port of the solid state amplifier module , and - a control unit for controlling the solid state power amplifier module to emit the high frequency radiation in the radio frequency range and/or microwave frequency range into the cavity for dielectric heating of the one or more objects placed therein, the control unit further configured for controlling the emission of the high frequency radiation in the radio frequency range and/or microwave frequency range for heating the one or more objects based on radio-frequency and/or microwave radiation reflected back from the cavity and received by a receiver module via the at least one antenna , wherein - the at least one solid state power amplifier module and the at least one antenna being integrated on a common printed circuit board layout , and - the control unit being configured for varying the frequency based on the radio-frequency and/or microwave radiation reflected back from the cavity and received by the receiver module. - at least one solid state power amplifier module with at least one input port and at least one output port , the solid state amplifier module configured for amplifying radio frequency and/or microwave frequency signals received at the input port , and for outputting the amplified radio frequency and/or microwave signals at the output port ; - at least one antenna coupled to the output port of the solid state amplifier module and at least configured for emitting radio frequency or microwave frequency radiation based on the signals from the output port of the solid state amplifier module , and - a control unit for controlling the solid state power amplifier module to emit the high frequency radiation in the radio frequency range and/or microwave frequency range into the cavity for dielectric heating of the one or more objects placed therein, the control unit further configured for controlling the emission of the high frequency radiation in the radio frequency range and/or microwave frequency range for heating the one or more objects based on radio-frequency and/or microwave radiation reflected back from the cavity and received by a receiver module via the at least one antenna , - the at least one solid state power amplifier module and the at least one antenna being integrated on a common printed circuit board layout , and - the control unit being configured for varying the frequency based on the radio-frequency and/or microwave radiation reflected back from the cavity and received by the receiver module. <EOS>