A high frequency signal amplifying circuitry comprising: a first splitter; a first Doherty amplifier including a second splitter for dividing a signal supplied from the first splitter to a first carrier amplifier, and to a first peak amplifier, and a first combiner for combining signals output from the first carrier amplifier and from the first peak amplifier, a second Doherty amplifier including a third splitter for dividing a signal supplied from the first splitter to a second carrier amplifier, and to a second peak amplifier, and a second combiner for combining signals output from the second carrier amplifier and from the second peak amplifier; and a third combiner for combining signals output from the first combiner and the second combiner; characterised by: a first loop oscillation suppressor including a first resistor (Rc-1, Rp-11); and wherein, either the second carrier amplifier is adjacent to the first carrier amplifier, or the second peak amplifier is adjacent to the first peak amplifier; if the second carrier amplifier is adjacent to the first carrier amplifier the following applies: the first loop oscillation suppressor is located between the second carrier amplifier and the first carrier amplifier, the first resistor (Rc-1) being connected between locations at the same potential of the second carrier amplifier and the first carrier amplifier so that a parasitic inductance of the first loop oscillation suppressor locating between the adjacent first and second carrier amplifiers (20A, 20B) can be made small; if the second peak amplifier is adjacent to the first peak amplifier the following applies: the first loop oscillation suppressor is located between the second peak amplifier and the first peak amplifier, the first resistor (RP-11) being connected between locations at the same potential of the second peak amplifier and the first peak amplifier, so that a parasitic inductance of the first loop oscillation suppressor locating between the adjacent first and second peak amplifiers (18A, 18B) can be made small. a first splitter; a first Doherty amplifier including a second splitter for dividing a signal supplied from the first splitter to a first carrier amplifier, and to a first peak amplifier, and a first combiner for combining signals output from the first carrier amplifier and from the first peak amplifier, a second Doherty amplifier including a third splitter for dividing a signal supplied from the first splitter to a second carrier amplifier, and to a second peak amplifier, and a second combiner for combining signals output from the second carrier amplifier and from the second peak amplifier; and a third combiner for combining signals output from the first combiner and the second combiner; characterised by: a first loop oscillation suppressor including a first resistor (Rc-1, Rp-11); and wherein, either the second carrier amplifier is adjacent to the first carrier amplifier, or the second peak amplifier is adjacent to the first peak amplifier; if the second carrier amplifier is adjacent to the first carrier amplifier the following applies: the first loop oscillation suppressor is located between the second carrier amplifier and the first carrier amplifier, the first resistor (Rc-1) being connected between locations at the same potential of the second carrier amplifier and the first carrier amplifier so that a parasitic inductance of the first loop oscillation suppressor locating between the adjacent first and second carrier amplifiers (20A, 20B) can be made small; if the second peak amplifier is adjacent to the first peak amplifier the following applies: the first loop oscillation suppressor is located between the second peak amplifier and the first peak amplifier, the first resistor (RP-11) being connected between locations at the same potential of the second peak amplifier and the first peak amplifier, so that a parasitic inductance of the first loop oscillation suppressor locating between the adjacent first and second peak amplifiers (18A, 18B) can be made small. a first loop oscillation suppressor including a first resistor (Rc-1, Rp-11); and wherein, either the second carrier amplifier is adjacent to the first carrier amplifier, or the second peak amplifier is adjacent to the first peak amplifier; if the second carrier amplifier is adjacent to the first carrier amplifier the following applies: the first loop oscillation suppressor is located between the second carrier amplifier and the first carrier amplifier, the first resistor (Rc-1) being connected between locations at the same potential of the second carrier amplifier and the first carrier amplifier so that a parasitic inductance of the first loop oscillation suppressor locating between the adjacent first and second carrier amplifiers (20A, 20B) can be made small; if the second peak amplifier is adjacent to the first peak amplifier the following applies: the first loop oscillation suppressor is located between the second peak amplifier and the first peak amplifier, the first resistor (RP-11) being connected between locations at the same potential of the second peak amplifier and the first peak amplifier, so that a parasitic inductance of the first loop oscillation suppressor locating between the adjacent first and second peak amplifiers (18A, 18B) can be made small.