Surgical cutting apparatus (100, 200, 300, 700, 800) having: a microwave radiation source (102, 202, 302, 360, 702, 802) arranged to generate a first microwave radiation signal having a first frequency and a second microwave radiation signal having a second frequency； a surgical instrument (104, 304, 400, 500, 600, 704, 804) having a cutting element comprising: a blade with a cutting edge (402, 404, 502, 504, 602, 604) for cutting biological tissue, and a first antenna (410, 510, 610) connectable to the source to receive the first microwave radiation signal and arranged to emit a substantially uniform microwave radiation field at the first frequency along the cutting edge of the cutting element blade , and a second antenna (416, 508, 611) connectable to the source to receive the second microwave radiation signal and arranged to emit from the surgical instrument a microwave radiation field at the second frequency, in which the second frequency it is less than the first frequency, and in which the edge (402, 404, 502, 504, 602, 604) of the cutting element blade comprises a radiating part for the first antenna (410, 510, 610), and the second antenna (416, 508, 611) is mounted adjacent to the fil or of the cutting element blade, whereby both antennas emit a substantially uniform microwave radiation field along the cutting edge of the cutting element blade.Aparato de corte quirúrgico (100, 200, 300, 700, 800) que tiene: una fuente de radiación de microondas (102, 202, 302, 360, 702, 802) dispuesta para generar una primera señal de radiación de microondas que tiene una primera frecuencia y una segunda señal de radiación de microondas que tiene una segunda frecuencia； un instrumento quirúrgico (104, 304, 400, 500, 600, 704, 804) que tiene un elemento cortante que comprende: una hoja con un filo (402, 404, 502, 504, 602, 604) para cortar tejido biológico, y una primera antena (410, 510, 610) conectable a la fuente para recibir la primera señal de radiación de microondas y d
