An electronic device, comprising: a radar system, implemented at least partially in hardware, configured to: provide a radar field; sense reflections from an input device (112, 1102, 1202, 1302) in the radar field to control applications on the electronic device; analyze the reflections from the input device (112, 1102, 1202, 1302) in the radar field; and provide, based on the analysis of the reflections, radar data; one or more computer processors (202, 1410); and one or more computer-readable media (204, 1414) having instructions stored thereon that, responsive to execution by the one or more computer processors (202, 1410), implement a radar-signature manager configured to: detect, based on a first subset of the radar data, a radar signature of a radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) of the input device (112, 1102, 1202, 1302) in the radar field, the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) being a component of the input device (112, 1102, 1202, 1302) producing a known radar signature when illuminated by the radar field; compare the detected radar signature to a benchmark radar signature that corresponds to a characteristic disposition of the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306); determine, based on the comparison, that the detected radar signature matches the benchmark radar signature; and responsive to the determination that the detected radar signature matches the benchmark radar signature, determine, based on the characteristic disposition of the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) that corresponds to the matched benchmark radar signature, a characteristic disposition of the input device (112, 1102, 1202, 1302) in the radar field. a radar system, implemented at least partially in hardware, configured to: provide a radar field; sense reflections from an input device (112, 1102, 1202, 1302) in the radar field to control applications on the electronic device; analyze the reflections from the input device (112, 1102, 1202, 1302) in the radar field; and provide, based on the analysis of the reflections, radar data; provide a radar field; sense reflections from an input device (112, 1102, 1202, 1302) in the radar field to control applications on the electronic device; analyze the reflections from the input device (112, 1102, 1202, 1302) in the radar field; and provide, based on the analysis of the reflections, radar data; one or more computer processors (202, 1410); and one or more computer-readable media (204, 1414) having instructions stored thereon that, responsive to execution by the one or more computer processors (202, 1410), implement a radar-signature manager configured to: detect, based on a first subset of the radar data, a radar signature of a radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) of the input device (112, 1102, 1202, 1302) in the radar field, the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) being a component of the input device (112, 1102, 1202, 1302) producing a known radar signature when illuminated by the radar field; compare the detected radar signature to a benchmark radar signature that corresponds to a characteristic disposition of the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306); determine, based on the comparison, that the detected radar signature matches the benchmark radar signature; and responsive to the determination that the detected radar signature matches the benchmark radar signature, determine, based on the characteristic disposition of the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) that corresponds to the matched benchmark radar signature, a characteristic disposition of the input device (112, 1102, 1202, 1302) in the radar field. detect, based on a first subset of the radar data, a radar signature of a radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) of the input device (112, 1102, 1202, 1302) in the radar field, the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) being a component of the input device (112, 1102, 1202, 1302) producing a known radar signature when illuminated by the radar field; compare the detected radar signature to a benchmark radar signature that corresponds to a characteristic disposition of the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306); determine, based on the comparison, that the detected radar signature matches the benchmark radar signature; and responsive to the determination that the detected radar signature matches the benchmark radar signature, determine, based on the characteristic disposition of the radar-image shaper (114, 700, 802, 804, 1204, 1206, 1304, 1306) that corresponds to the matched benchmark radar signature, a characteristic disposition of the input device (112, 1102, 1202, 1302) in the radar field.