Abstract: A method allows determination of a frequency interval for the emission, by an item of user equipment, of a signal to be sent to a base station in a telecommunications network, the frequency interval being within a predetermined frequency band over which the base station works, the method including the determination of frequency interval, wherein the determination of the frequency interval is achieved from a table of references including maximum power reduction values for the emission of a signal by the item of user equipment so that the power of the signal emitted by the item of user equipment at a predetermined out-of-band frequency is less than a predetermined maximum power limit value.

Abstract: A filtering device intended for being connected to a portable mobile terminal compatible with a PMR network having a wide range of receiving frequencies Bi, includes a fastening system for fastening to the mobile terminal, a first radio-frequency connector intended for engaging with a radio-frequency connector of the mobile terminal, a first channel including a first filter for filtering a first receiving useful band Bui included within the band Bi, and a second radio-frequency connector intended for engaging with a removable RF antenna to transmit or receive radio-frequency signals.

Abstract: A filtering device intended for being connected to a portable mobile terminal compatible with a PMR network having a wide range of receiving frequencies Bi, includes a fastening system for fastening to the mobile terminal, a first radio-frequency connector intended for engaging with a radio-frequency connector of the mobile terminal, a first channel including a first filter for filtering a first receiving useful band Bui included within the band Bi, and a second radio-frequency connector intended for engaging with a removable RF antenna to transmit or receive radio-frequency signals.

Abstract: A method allows determination of a frequency interval for the emission, by an item of user equipment, of a signal to be sent to a base station in a telecommunications network, the frequency interval being within a predetermined frequency band over which the base station works, the method including the determination of frequency interval, wherein the determination of the frequency interval is achieved from a table of references including maximum power reduction values for the emission of a signal by the item of user equipment so that the power of the signal emitted by the item of user equipment at a predetermined out-of-band frequency is less than a predetermined maximum power limit value.

Abstract: A wireless communication unit (100) comprises a transmitter (120) arranged to transmit an envelope modulated signal. The transmitter (120) comprises a radio frequency power amplifier (124) operably coupled to a logarithmic detector (210, 310) and a bias control circuit (126) arranged to set a direct current bias level of the radio frequency power amplifier (124) via a bias signal. The logarithmic detector (210, 310) is arranged to detect the envelope modulated signal and provide the detected envelope modulated signal to the bias control circuit such that the bias signal applied to the radio frequency power amplifier (124) comprises both a direct current and a low frequency component based on the detected envelope modulated signal. In this manner, the present invention supports a tradeoff of linearity for additional efficiency, as well as providing more margin on adjacent channel power levels, whilst maintaining a good overall power added efficiency.